Question

If (8z − 9)(8z + 9) = az2 − b, what is the value of a?

The value of a is ____________.

Numerical Answers

Answer 1

*az^2

Answer 2

Use the foil method to expand (8z-9)(8z+9)

Answer 3

foil method? whats that? @Vocaloid

Answer 4

First, outer, inner, last

(8z+9)(8z-9) = (8z)(8z) - (8z)(9) + (8z)(9) - (9)(9)

Answer 5

Simplify that and tell me what you get

Answer 6

ok

Answer 7

64z^2-81?

Answer 8

@Vocaloid

Answer 9

Yes.

So we know that

az^2 - b = 64z^2 - 9

Now, what do you think is the value of a?

Answer 10

64

Answer 11

Right, good job

Answer 12

ty :)