Question

Kak help me ya ka...
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Answer 1

11. misalkan sepatu = x
kaos = y

2x+3y = 85000  | ×3
3x+y   = 75000  | ×2
----------------------------
6x+9y = 255000
6x+2y = 150000 - 
------------------------
7y = 105000
y = 105000:7
y = 15000

3x+y = 75000
3x+15000 = 75000
3x = 75000-15000
3x = 60000
x = 60000:3
x = 20000

5x+4y = 5×20000+4×15000
5x+4y = 100000+60000
5x+4y = 160000

Jawaban: A

12. misalkan susu = x
donat = y

2x+2y = 66000    | ×2
4x+3y = 117000   | ×1
-----------------------------
4x+4y = 132000
4x+3y = 117000 -
-----------------------
y = 15000

2x+2y = 66000
2x+2×15000 = 66000
2x+30000 = 66000
2x = 66000-30000
2x = 36000
x = 36000:2
x = 18000

2x+5y = 2×18000+5×15000
2x+5y = 36000+75000
2x+5y = 111000

Jawaban: D

13. Jawaban: B

14. x²-36 = 0
Bentuk selisih kuadrat x²-y² yang faktornya (x+y)(x-y)
(x+6)(x-6) = 0
x = -6 atau x = 6

Jawaban: C

15. 9x²-16 = 0
Bentuk selisih kuadrat
(3x+4)(3x-4) = 0
x = -4/3 atau x = 4/3

Jawaban: A