Select all the expressions that are equivalent to the polynomial below. -15x^2-29x-12 (-17x2 + 2x − 3) + (2x2 − 31x − 9) (5x2 − 10x + 8) − (10x2 + 19x + 20) -2(7x + 1) − 5(3x2 + 3x + 2) -2(4x − 15) − 3(5x2 + 7x + 6) (-19x2 − 4x - 7) + (4x2 + 25x − 5) (-7x2 − 21x + 13) − (8x2 + 8x + 25)

1,3 and 5

Step-by-step explanation:

1) -2(7x + 1) − 5(3x2 + 3x + 2)

= -14x - 2 - 15x^2 - 15x - 10

= -15x^2 - 29x - 12

2) (5x2 − 10x + 8) − (10x2 + 19x + 20)

= 5x^2 - 10x + 8 - 10x^2 - 19x - 20

= -5x^2 -29x - 12

3) (-7x2 − 21x + 13) − (8x2 + 8x + 25)

= -7x^2 - 21x + 13 - 8x^2 - 8x - 25

= -15x^2 - 29x - 12

4) (-19x2 − 4x - 7) + (4x2 + 25x − 5)

= -15x^2 + 21x - 12

5) (-17x2 + 2x − 3) + (2x2 − 31x − 9)

= -15x^2 -29x - 12

6) -2(4x − 15) − 3(5x2 + 7x + 6)

= -8x + 30 - 15x^2 - 21x - 18

= -15x^2 - 29x + 12

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.