Algebra Examples
y=8y=8 , x=2x=2 , z=-7z=−7
Step 1
When three variable quantities have a constant ratio, their relationship is called a direct variation. It is said that one variable varies directly as the other two vary. The formula for direct variation is y=kxz2y=kxz2, where kk is the constant of variation.
y=kxz2y=kxz2
Step 2
Solve the equation for kk, the constant of variation.
k=yxz2k=yxz2
Step 3
Replace the variables xx, yy, and zz with the actual values.
k=8(2)⋅(-7)2k=8(2)⋅(−7)2
Step 4
Step 4.1
Factor 22 out of 88.
k=2⋅42⋅(-7)2k=2⋅42⋅(−7)2
Step 4.2
Cancel the common factors.
Step 4.2.1
Factor 22 out of 2⋅(-7)22⋅(−7)2.
k=2⋅42((-7)2)k=2⋅42((−7)2)
Step 4.2.2
Cancel the common factor.
k=2⋅42(-7)2
Step 4.2.3
Rewrite the expression.
k=4(-7)2
k=4(-7)2
k=4(-7)2
Step 5
Raise -7 to the power of 2.
k=449
Step 6
Write the equation of variation such that y=kxz2, replacing k with the 449.
y=4xz249