Xander started doing his homework at 3:45 PM, and he finished at 5:30 PM. How many hours and minutes did it take him to complete his homework?

A. 1 hour and 15 minutes
B. 1 hour and 45 minutes
C. 2 hours and 15 minutes
D. 1 hour and 30 minutes

2x+3y=7 2(2)+3y=7 4+3y=7 subtract 4 from both sides 3y=3 divide both side by 3 y=1
2x+3y=7
2x+3=7
2x+3y=7
subtract 3y from both sides
2x=7-3y
divide both side by 2
x=3.5-1.5
x=2

then you do the x-y=1
x-y=1 2-1=1 1=1
in the end both answers are 1 so that means that i did it right. that means that x=2 and y=1

Answered by 17rajohnson | 2024-06-10

2x+3y=7 x-y=1
2x+3y=7 x=1+y
2*(1+y)+3y=7 x=1+y
2+2y+3y=7 x=1+y
5y=5 |(:5) x=1+y
y=1 x=2
CHECK: 2x+3y=7 x-y=1
2 2 + 3 1 = 7
x-y = 1 2-1 = 1

Answered by kamil | 2024-06-10

To solve the system of equations 2 x + 3 y = 7 and x − y = 1 , you can substitute x from the second equation into the first. This leads to y = 1 and consequently x = 2 . The final solution is x = 2 and y = 1 .
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Answered by 17rajohnson | 2025-01-30