Question

Which value for x makes the open sentence true?
7 + 6 • x = 4^2 + x^2

a) 5
b) 4
c) 3
d) 2

Answer 1

Change it to standard form first
ax^2 + bx + c = 0

x^2 - 6x + 9 = 0

can you factor that now

Answer 2

@AloneS

Answer 3

Recall the zero-product property ab=0 if and only if a=0 or b=0.

Answer 4

But there is no a or b.... there's x. I'm confused.

Answer 5

The "a or b" stands for any variable :-)

Answer 6

Do you see how DanJS got x^2 -6x +9 = 0?

Answer 7

Nope, no idea.

Answer 8

$$7 + 6 • x = 4^2 + x^2$$

$$7 + 6 • x -7-6•x= 4^2 + x^2-7-6•x$$

Answer 9

Subtract 7 and 6•x from both sides.

Answer 10

So then, on the left side of the equal sign, would it be x^2?

Answer 11

Nope, it would be 0.

Answer 12

Alright I think I can figure it out now. Thanks.

Answer 13

Thanks for trying :-)