Randy is thinking of a number. When he adds 7 to the number, multiplies the sum by 3, then subtracts 2, the result is 13. What is the original number? A. 6
B. -2
C. 2
D. -6

Step-by-step explanation:

let the number be x

=7+x

=3(7+x)

=3(7+x)-2

13=3(7+x)-2

solving for  x we have

13=21+3x-2

21+3x-2-13=0

collect like terms we have

21-2-13+3x=0

6+3x=0

6=-3x

x=6/-3

x=-2

The answer is B

B. -2

22 dimes and 9 nickels

step-by-step explanation:

"standard form:

3x2 + 14x − 10 = 0

solutions based on quadratic formula:

x1   = −14 − √ 142 − 4×3×(−10) /   2×3   = −14 − 2 × √ 79 /   6   ≈ −5.296

x2   = −14 + √ 142 − 4×3×(−10) /   2×3   = −14 + 2 × √ 79 /   6   ≈ 0.629