Question

Twice the sum of a number and 3 is equal to three times the difference of the number and 7. Find the number

Answer 1

Answer:

The number is 27

Step-by-step explanation:

Let us change the word statement to an algebraic equation

→ Assume that the number is x

→ Twice the sum of a number and 3, means add x by 3, then multiply the sum by 2

→ The algebraic expression is 2(x + 3)

→ Three times the difference of the number and 7, means subtract x and 7, then multiply the difference by 3

→ The algebraic expression is 3(x - 7)

→ Equate the two expressions

∴ 2(x + 3) = 3(x - 7)

→ Simplify each side

∵ 2(x + 3) = 2(x) + 2(3) = 2x + 6

∵ 3(x - 7) = 3(x) - 3(7) = 3x - 21

∴ 2x + 6 = 3x - 21

Let us solve the equation to find x

→ Subtract 6 from both sides

∴ 2x + 6 - 6 = 3x -21 - 6

∴ 2x = 3x - 21

→ Subtract 3x from both sides

∴ 2x - 3x = 3x - 3x - 27

∴ -x = -27

→ Divide both sides by -1

∴ x = 27

The number is 27