mohonn dikawabbb yaaa

18) 2x + 6y = 70
=> x + 3y = 35
=> 3y = 35 - x
=> y = (35 - x)/3

3x^2 + 5y = 125
3x^2 + 5(35 - x)/3 = 125 ====> kedua ruas dikali 3
9x^2 + 5(35 - x) = 375
9x^2 + 175 - 5x - 375 = 0
9x^2 - 5x - 200 = 0
(9x + 40)(x - 5) = 0
x = -40/9 atau x = 5

y = (35 - x)/3
x = 5 => y = (35 - 5)/3 = 10
x = 5 dan y = 10

ATAU

x = -40/9 => y = (35 - (-40/9)/3 . 9/9 = (315 + 40)/27 = 355/27
x = -4,45 dan y = 13,15

2) log ^3√10.000.000 = log 10^(7/3) = 7/3 (log 10) = 7/3 . 1 = 7/3

4 . 2log2 - 2log2^3 + 2log ^3√(1/4)
= 4 . 2log2 - 2log2^3 + 2log2^(-2/3)
= 4 . 2log2 - 3 . 2log2 + (-2/3) 2log2
= 4 . 1 - 3 . 1 - 2/3 . 1
= 4 - 3 - 2/3
= 1/3

Hasil pembagiannya = (7/3) / (1/3) = 7