x-y = 6
x^2-y^2 = 120
x+y = 120/6 = 20
13 and 7
Two number differs by 6 the difference between their square is120 find the numbers
2 answers
x - y = 6 , #1
x^2 - y^2 = 120
(x+y)(x-y) = 120
sub in #1
(x+y)(6) = 120
x + y = 20, #2
add #1 and #1
2x = 26
x = 13
in x+y = 20
13 + y = 20
y = 7
the numbers are 13 and 7
x^2 - y^2 = 120
(x+y)(x-y) = 120
sub in #1
(x+y)(6) = 120
x + y = 20, #2
add #1 and #1
2x = 26
x = 13
in x+y = 20
13 + y = 20
y = 7
the numbers are 13 and 7
3 answers