Question

sabendo que x+y=5 e que x-y=1,determine o valor de
3x+3y=
7x-7y=
x²-y²=
x²+2xy+y²=

Answer 1

x + y = 5
x - y = 1
2x = 6
x = 6/2
x = 3

x + y = 5
3 + y = 5
y = 5 - 3
y = 2

a)
= 3x + 3y
= 3.3 +3.2
= 9 + 6
= 15

b)
= 7x - 7y
= 7.3 - 7.2
= 21 - 14
= 7

c)
= x²  - y²
= 3² - 2²
= 9 - 4
= 5

d)
= x² + 2xy + y²
= 3² + 2.3.2 + 2²
= 9 + 12 + 4
= 21 + 4
= 25