I think of a number. I multiply it by 5 and then add 7 The answer is 22 What number was I thinking of?

The number  x = 3

Step-by-step explanation:

Explanation

Let 'x' be a number

Given that  multiply it by 5 and then add 7 The answer is 22

5 x + 7 = 22

subtracting '7' on both sides, we get

5 x + 7 - 7 = 22 -7

5 x  = 15

Dividing by '5' on both sides, we get

x = 3

The number  x = 3

11 boxes of cards for $72

Step-by-step explanation:

Brennan's equation would be

y=6x+6

Gabriel's Equation would be

y=5x+17

when they spend the same amount the equations will be equal

6x+6=5x+17

x+6= 11

x=11

so 11 boxes they would spend the same

To figure out cost, put 11 into the first equations

y=6(11)+6= 66+6= 72

y=5(11)+17= 55+17 = 72

so they each spent $72