To solve for the x, distribute first the numerical coefficients to the terms on the parentheses. This becomes,

7x - 21 = 4x + 20

Transpose all the terms with x and the constant on either sides of the equation,

   7x - 4x = 20 + 21

  3x = 41 ; x = 41 / 3

Thus, the answer is x = 41/3 which is fourth among the choices.

6 0

4 years ago

Zoe thinks of a number. She multiplies it by 3 and adds 4. She gets the same answer when she adds 5 to the number and then multi

Fiesta28 [93]

Answer:

Zoe's number is 6

Step-by-step explanation:

Let the number be 'n'

a) Multiply 'n' by 3 ⇒ n*3 = 3n

Add 4 to '3n' ⇒ 3n + 4

Add 5 to 'n' ⇒ n +5

Multiply (n+ 5) by 2 ⇒ (n +5)*2 = 2n + 5*2 = 2n + 10

3n + 4 = 2n + 10

b) 3n + 4 = 2n + 10

Subtract 4 form both sides

3n = 2n + 10 - 4

3n = 2n + 6

Subtract 2n from both sides

3n - 2n = 6

$\sf \boxed{\bf n = 6}$

8 0

2 years ago

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