I need help..
5x-3+3x+7 if x=3

28

Step-by-step explanation:

Replace x with 3, and multiply the number next to it.

5(3)= 15

3(3)=9

so, 15-3+9+7=28

28

Step-by-step explanation:

To solve this, replace every x with (3). If x is next to a number, that means you multiply that number and the value of x. This gives us the equation 5(3)-3+3(3)+7. When a set of parentheses are next to a number, you multiply. 5 times three is 15, and 3 times 3 is 9. This gives us 15-3+9+7. 15 - 3 is 12. 12 + 9 is 21. 21 + 7 is 28. 28 is your answer.

idk

step-by-step explanation:

i don't know

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.