In 2016 Alphonse grew twice the number of grapes that Pierre did. In 2017 Pierre grew twice the number of grapes that Alphonse did. Over the two years Alphonse grew 49000 grapes which was 7600 less than Pierre. How many grapes did Alphonse grow in 2016?
+128460 Let x be the number of grapes that Pierre grew in 2016.......then 2x was the number that Alphonse grew that year
And let y be the number of grapes that Alphonse grew in 2017.....then 2y was the number that Pierre grew that year
So we have that
2x + y = 49000 = number of grapes that Alphonse grew over the two years
x + 2y = 49000 + 7600 = number of grapes that Pierre grew over the two years
Simplify
2x + y = 49000
x + 2y = 56600
Multiply the 1st equation by -2 and we have
-4x - 2y = -98000
x + 2y = 56600 add these equations
-3x = -41400 divide both sides by -3
x = 13800
And Alphonse grew twice as many in 2016 = 27600
