Simplify the expression 7(a-3+4b)

7a - 21 + 28b

Step-by-step explanation:

using the distributive property we can multiply 7 to the numbers in the paretheses. doing this we get:

7a - 21 + 28b

im pretty sure it would be 5 am, hope that , and give brainliest and guys if this is right then press the button and give 5 stars

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.