Problem of the Week

Updated at Mar 17, 2025 2:56 PM

For this week we've brought you this equation problem.

How would you solve 8z(z+2)5=645\frac{8z(z+2)}{5}=\frac{64}{5}?

Here are the steps:



8z(z+2)5=645\frac{8z(z+2)}{5}=\frac{64}{5}

1
Multiply both sides by 55.
8z(z+2)=648z(z+2)=64

2
Expand.
8z2+16z=648{z}^{2}+16z=64

3
Move all terms to one side.
8z2+16z−64=08{z}^{2}+16z-64=0

4
Factor out the common term 88.
8(z2+2z−8)=08({z}^{2}+2z-8)=0

5
Factor z2+2z−8{z}^{2}+2z-8.
8(z−2)(z+4)=08(z-2)(z+4)=0

6
Solve for zz.
z=2,−4z=2,-4

Done
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