Question

Sally has 3 times as many pencil erasers as Sam Together they have 28 erasers how many erasers does Sally have​

Answer 1

Answer: 21.

Explanation:

Sally=x, Sam=y

x=3y

x+y=28

Substitution works. Since we know x is 3y, we can substitute the x in the second equation for 3y.

3y+y=28 ---> 4y=28

Divide both sides by 4 and y=7. You can plug in y to either equation, but the first one seems easier.

x=3(7)

x=21

Answer 2

Answer: 21 Erasers

Explanation:

Let x be the number of pencil erasers that Sam has.

Sally has 3x pencil erasers.

Together, they have x + 3x = 28 erasers.

4x = 28

x = 7 erasers.

Sally has 3 * 7 = 21 erasers.

So the answer is 21