Examples
[2347]⋅[xy]=[11][2347]⋅[xy]=[11]
Step 1
Step 1.1
Two matrices can be multiplied if and only if the number of columns in the first matrix is equal to the number of rows in the second matrix. In this case, the first matrix is 2×22×2 and the second matrix is 2×12×1.
Step 1.2
Multiply each row in the first matrix by each column in the second matrix.
[2x+3y4x+7y]=[11][2x+3y4x+7y]=[11]
[2x+3y4x+7y]=[11][2x+3y4x+7y]=[11]
Step 2
Write as a linear system of equations.
2x+3y=12x+3y=1
4x+7y=14x+7y=1
Step 3
Step 3.1
Solve for xx in 2x+3y=12x+3y=1.
Step 3.1.1
Subtract 3y3y from both sides of the equation.
2x=1-3y2x=1−3y
4x+7y=14x+7y=1
Step 3.1.2
Divide each term in 2x=1-3y2x=1−3y by 22 and simplify.
Step 3.1.2.1
Divide each term in 2x=1-3y2x=1−3y by 22.
2x2=12+-3y22x2=12+−3y2
4x+7y=14x+7y=1
Step 3.1.2.2
Simplify the left side.
Step 3.1.2.2.1
Cancel the common factor of 22.
Step 3.1.2.2.1.1
Cancel the common factor.
2x2=12+-3y2
4x+7y=1
Step 3.1.2.2.1.2
Divide x by 1.
x=12+-3y2
4x+7y=1
x=12+-3y2
4x+7y=1
x=12+-3y2
4x+7y=1
Step 3.1.2.3
Simplify the right side.
Step 3.1.2.3.1
Move the negative in front of the fraction.
x=12-3y2
4x+7y=1
x=12-3y2
4x+7y=1
x=12-3y2
4x+7y=1
x=12-3y2
4x+7y=1
Step 3.2
Replace all occurrences of x with 12-3y2 in each equation.
Step 3.2.1
Replace all occurrences of x in 4x+7y=1 with 12-3y2.
4(12-3y2)+7y=1
x=12-3y2
Step 3.2.2
Simplify the left side.
Step 3.2.2.1
Simplify 4(12-3y2)+7y.
Step 3.2.2.1.1
Simplify each term.
Step 3.2.2.1.1.1
Apply the distributive property.
4(12)+4(-3y2)+7y=1
x=12-3y2
Step 3.2.2.1.1.2
Cancel the common factor of 2.
Step 3.2.2.1.1.2.1
Factor 2 out of 4.
2(2)(12)+4(-3y2)+7y=1
x=12-3y2
Step 3.2.2.1.1.2.2
Cancel the common factor.
2⋅(2(12))+4(-3y2)+7y=1
x=12-3y2
Step 3.2.2.1.1.2.3
Rewrite the expression.
2+4(-3y2)+7y=1
x=12-3y2
2+4(-3y2)+7y=1
x=12-3y2
Step 3.2.2.1.1.3
Cancel the common factor of 2.
Step 3.2.2.1.1.3.1
Move the leading negative in -3y2 into the numerator.
2+4(-3y2)+7y=1
x=12-3y2
Step 3.2.2.1.1.3.2
Factor 2 out of 4.
2+2(2)(-3y2)+7y=1
x=12-3y2
Step 3.2.2.1.1.3.3
Cancel the common factor.
2+2⋅(2(-3y2))+7y=1
x=12-3y2
Step 3.2.2.1.1.3.4
Rewrite the expression.
2+2(-3y)+7y=1
x=12-3y2
2+2(-3y)+7y=1
x=12-3y2
Step 3.2.2.1.1.4
Multiply -3 by 2.
2-6y+7y=1
x=12-3y2
2-6y+7y=1
x=12-3y2
Step 3.2.2.1.2
Add -6y and 7y.
2+y=1
x=12-3y2
2+y=1
x=12-3y2
2+y=1
x=12-3y2
2+y=1
x=12-3y2
Step 3.3
Move all terms not containing y to the right side of the equation.
Step 3.3.1
Subtract 2 from both sides of the equation.
y=1-2
x=12-3y2
Step 3.3.2
Subtract 2 from 1.
y=-1
x=12-3y2
y=-1
x=12-3y2
Step 3.4
Replace all occurrences of y with -1 in each equation.
Step 3.4.1
Replace all occurrences of y in x=12-3y2 with -1.
x=12-3(-1)2
y=-1
Step 3.4.2
Simplify the right side.
Step 3.4.2.1
Simplify 12-3(-1)2.
Step 3.4.2.1.1
Combine the numerators over the common denominator.
x=1-3⋅-12
y=-1
Step 3.4.2.1.2
Simplify the expression.
Step 3.4.2.1.2.1
Multiply -3 by -1.
x=1+32
y=-1
Step 3.4.2.1.2.2
Add 1 and 3.
x=42
y=-1
Step 3.4.2.1.2.3
Divide 4 by 2.
x=2
y=-1
x=2
y=-1
x=2
y=-1
x=2
y=-1
x=2
y=-1
Step 3.5
List all of the solutions.
x=2,y=-1
x=2,y=-1