Well for two positive numbers subtracted to equal a negative number, the first number must have a value that is less than the second number. (Ex. 3-4= -1) In this case, you can conclude that x is less than y! (x<y)
Sqrt -13 = sqrt13 i
sqrt -26 = sqrt2 * sqrt13i
sqrt-13 * sqrt -26 = sqrt2 * 13* i^2 = -13 sqrt2 (because i^2 = -1)
answer is -13 sqrt2
Twenty percent of $35 is 0.20($35) = $7. The discount is $7.
The answer is (5x - 4y)(2a + b)
10ax + 5bx - 8ay - 4by = 10ax + 5bx - (8ay + 4by) =<span>
= 5x * 2a + 5x * b - (2a * 4y + b * 4y) =
= 5x(2a + b) - 4y(2a + b) =
= (5x - 4y)(2a + b)</span>
