Mathematics: which of the following are solutions to the equation below x^2+4x-9=x+1 check all that apply a. 2 b. 4 c. -7 d. -3 e. -5 f. -4

NoStep-by-step explanation:3x • 6x + 1 + 42 + -2x=16x+43...

which of the following are solutions to the equation

Joyfull546

31.01.2022

a. and e.

Step-by-step explanation:

Hello, there are two ways to handle this kind of question.

... Either you solve the equation ...

$x^2+4x-9=x+1\\\\x^2+3x-10=0\\\\x^2-2x+5x-10=x(x-2)+5(x-2)=(x+5)(x-2)=0\\\\x= -5 \ \ or \ \ x = 2$

So the right answers are a. and e.

... Or, you check which answer can be right.

We replace x by 2 and the two expressions are equal.

$2^2+4*2-9=4+8-9=3 \ and \ 2+1=3$

So this is a. 2

We replace x by 4 and the two expressions are not equal.

$4^2+4*4-9=16+16-9=23 \ and \ 4+1=5$

So this is not b. 4

We replace x by -7 and the two expressions are not equal.

$7^2-4*7+9=49-28+9=30 \ and \ -7+1=-6$

So this is not c. -7

We replace x by -3 and the two expressions are not equal.

$3^2-4*3-9=9-12-9=-12 \ and \ -3+1=-2$

So this is not d. -3

We replace x by -5 and the two expressions are equal.

$5^2-4*5-9=25-20-9=-4 \ and \ -5+1=-4$

So this is e. -5

We replace x by -4 and the two expressions are not equal.

$4^2-4*4-9=16-16-9=-9 \ and \ -4+1=-3$

So this is not f. -4

Thank you.

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