5(x^2 + y)
2(x+y) is twice the sum of x and y, and 2x+y is the sum of twice x and y
x - (y + 2)
3[(x^2) + 5] x (2x-y) Do the parentheses first, then brackets next. P.e.m.d.a.s.
It can be, it need not be.
5(x^2 + y)
Twice the sum of 'x' and 'y' . . . 2(x+y) The sum of twice 'x' and 'y' . . . (2x+y)
2(x+y) is twice the sum of x and y, and 2x+y is the sum of twice x and y
2(x+y)=2x+2y
x - (y + 2)
2(y + 5)
(x + y)/2 ------------
x+y=6x^2 + y^2=20 x=2 and y=4 or vice versa
3[(x^2) + 5] x (2x-y) Do the parentheses first, then brackets next. P.e.m.d.a.s.
That verbal expression would read: 3(x+y)^2 + 5(2x -y) ^2 means 'squared' in the above example.
You can expand (x + y)2 into x2 + 2xy + y2
1/2 (x+y)