Question

3)
If x + y = 7and x - y = 3 find xy

10
12
15​

Answer 1

Answer:

xy=10

Step-by-step explanation:

x=5

substitute x in x+y=7

y=2

Answer 2

Answer:

xy=10

Step-by-step explanation:

$4xy=(x+y)^2-(x-y)^2\\4xy=7^2-3^2\\4xy=49-9\\xy=40/4=10\\\\\therefore xy=10$

<hope it helps>

<3