Evaluate the expression 7x2−12x+13 when x=4. Show each step of your work by using the math keyboard under this question. First, show the value substituted in for x. Then show each step and rewrite the problem until it is complete

-21

Step-by-step explanation:

7 x 2=14

14-48+13

14-48=-34

-34+13=-21

1. 180°. the sum of the interior angles of a triangle is 180°, for the equilateral triangle that it has three equals side is 60°+60°+60°=180°.

2. 60°. each interior angle of a equilateral triangle is 60°

3. 120°. the measure of ∠m is 120°, the sum of the angles ∠m and ∠n is equal to 180°. so, in order to find the measure of ∠m, we have ∠m+∠n=180° > ∠m=180°-∠n > ∠m=180°-60°=120°.

4. 360°. the sum of the exterior angles of an equilateral triangle is ∠m+∠r+∠x=120°+120°+120°=360°. the exterior angles of any triangle always add 360°.