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Be aware: The solution/the answer by other tutor is D E A D L Y W R O N G.
Below please find a correct solution.
8x + 2y = 1260 (1)
10x + 5y = 1950 (2)
Multiply eq(1) by 5. Multiply eq(2) by 4. You will get
40x + 10y = 5*1260 (1')
40x + 20y = 4*1950 (2')
Subtract eq(1') from eq(2'). You will get
10y = 4*1950 - 5*1260 = 1500 ====> y = = 150 dollars.
Then from (1), x = = 120 dollars.
Answer. $120 for bricklayer; $150 for roofer.
Check. 120*8 + 150*2 = 1260 ! Correct !
120*10 + 150*5 = 1950 ! Correct !
Solved.