-37
1 x 30, 2 x 15, 3 x 10, 5 x 6, 6 x 5, 10 x 3, 15 x 2, 30 x 1.
Let the numbers be x and y, then x + y = 60 (which yields y = 60 - x) xy = 1600 (replace y with 60 - x) x(60 - x) = 1600 60x - x2 = 1600 (multiply by -1 to both sides) x2 - 60x = -1600 (add 302 to both sides to complete the square) x2 - 60x + 302 = -1600 + 900 (x - 30)2 = -700 (take the square root of both sides) x - 30 = ± √-700 (add 30 to both sides and write -700 = (100)(7)(-1)) x = 30 ± (√100)(√7)(√-1) x = 30 ± (10√7)i So, x = 30 + (10√7)i or x = 30 - (10√7)i thus, y = 60 - [30 + (10√7)i] or y = 60 - [30 - (10√7)i ] y = 30 - (10√7)i or y = 30 + (10√7)i Therefore, [30 + (10√7)i] + [30 - (10√7)i] = 60 [30 + (10√7)i] [30 - (10√7)i] = 1600 Check:
10 x 3 = 30
x^2+7x-30 = (x-3)(x+10)
10% of 30 = 10% x 30 = 0.10 x 30 = 3
10% of 30% = 0.10 x 0.30 = 0.03 = 3%
20
10,000,000,000 x 0.000001=
3/10 = .3 = 30%or3/10 = (3 x 10)/(10 x 10) = 30/100 = 30%
x^2 + 13x + 30 = 0 x^2 + 10x + 3x + 30 = 0 x(x + 10) + 3(x + 10) = 0 (x + 3)(x + 10) = 0 x = -3 or x = -10
Solution: x + x + x = 30 3x = 30 x = 30/3 x = 10
-37
10 x 30 = 300
30 = (3 x 10) + (0 x 1)
2 x 5 = 10 2 x 3 x 5 = 30
30 = 10 x 3 x 1