Finding Unknown Number in an Equation

Solve this equation

a - 2.1 = 5.8

• a = 7.9

• a = 3.7

• a = 5.8

• None of these match my answer

Select all equations that are represented in this diagram.

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Which equation has x = 5 as the solution?

• x + 15 = 10

• 2x = 5

• 2x = 10

• x/2 = 10

Write an equation for each of these, use 'n' for the unknown number.

Do not include spaces between numbers and the equals sign.

I think of a number. I subtract 7. The answer is 16.

Write an equation for each of these, use 'n' for the unknown number.

Do not include spaces between numbers and the equals sign, use a / for divide.

I think of a number. I divide it by 9. The answer is 4.

Write an equation for each of these, use 'n' for the unknown number.

Do not include spaces between numbers and the equals sign, use a / for divide.

I think of a number. I multiply it by 3 and the answer is 18.

Write an equation for each of these, use 'n' for the unknown number.

Do not include spaces between numbers and the equals sign, use a / for divide.

I think of a number. I add 12, the answer is 20.

Write an equation for each of these, use 'n' for the unknown number.

Do not include spaces between numbers and the equals sign, use a / for divide.

I think of a number, multiply it by 3 then add 7, the answer is 19.

Write an equation for each of these, use 'n' for the unknown number.

Do not include spaces between numbers and the equals sign, use a / for divide.

I think of a number, then add 2, the multiply the result by 4. The answer is 36.

Write an equation for each of these, use 'n' for the unknown number.

Do not include spaces between numbers and the equals sign, use a / for divide.

Three more than double a number is 15