2. Three more than four times a number is 15.

The number is 3

Step-by-step explanation:

Let the number be x

Four times a number = 4 *x = 4x

Three more than four times a number = 4x + 3

4x +3 = 15

Subtract 3 from both sides

4x + 3 - 3 = 15 -3

            4x = 12

Divide both sides by 4

           4x/4x = 12/4

x = 3

x = 10.1

step-by-step explanation:

all of the angles of a tirangle add up to 180º

180 - 65 = 115 (since we already know the value of one angle)

(2x + 7) + (8x + 7) = 115

(combins like terms) 10x + 14 = 115

(isolate the variable subtract 14 from both sides): 10x = 101

(find the variable divide both sides by 10): x = 101/10

x = 10.1

10000

step-by-step explanation: divide by 2,