Factor the expression. 21x^2 + 43x + 20 (7x – 5)(3x – 4) (7x + 5)(3x + 4) (7x – 5)(3x + 4) (7x + 5)(3x – 4)

Each choice has 7x and 3x which multiply to 21x^2.
The original trinomial has positive 20 and positive 43, so all factors of 21 and of 20 must be positive.
Only choice B has all positive terms, so choice B must be the answer.

Hello,

This polygon has 4 sides
180(4-2) = 180(2) = 360 degree
80+90+2x + 3x = 360
170+5x = 360
5x = 190
x= 38
measure of angle t is 2(38)= 76
the answer is c. trust me
hope this !