Solve the following systems of equations:
7(y + 3) – 2(x + 2) = 14
4(y – 2) + 3(x – 3) = 2
Answers
Point of intersection will be (5, 1)
Step-by-step explanation:
7(y + 3) – 2(x + 2) = 14
7y + 21 - 2x - 4 = 14
-2x + 7y = -3 -------------(1)
4(y – 2) + 3(x – 3) = 2
4y - 8 + 3x - 9 = 2
3x + 4y = 19 -------------(2)
Adding equations (1)*3 & (2)*2, we get: 29y = +29. So y = 29/29 = 1
Substituting y = 1 in equation 1, we get: -2x + 7 = -3
-2x = - 10
x = 5
Hence solved. x = 5 and y = 1.
If you draw a graph for the equations, you will get two straight lines. The co-ordinates of the point of intersection of the two lines will be the solution. The point of intersection will be (5, 1)
Given,
7(y + 3) - 2(x + 2) = 14 .............(1)
4(y - 2) + 3(x - 3) = 2 ................(2)
Now,
From (1) we have,
7y + 21 - 2x - 4 = 14
7y = 14 + 4 - 21 + 2x
7y = 18 - 21 + 2x
7y = 2x - 3
y = (2x - 3)/7 ........... (3)
Also,
From (2) we have,
4y - 8 + 3x - 9 = 2
4y + 3x - 17 - 2 = 0
4y + 3x - 19 = 0 …........(4)
Putting value of y from (3) in (4) we get :-
4(2x - 3)/7 + 3x - 19 = 0
(8x - 12)/7 + 3x = 19
(8x - 12 + 7 × 3x)/7 = 19
(8x - 12 + 21x) = 19 × 7
29x - 12 = 133
29x = 133 + 12
29x = 145
x = 145/29
x = 5
Now,
Substituting value of x in (3),
y = (2x - 3)/7
y = (2 × 5 - 3)/7
y = (10 - 3)/7
y = 7/7
y = 1
Therefore,
x = 5 and y = 1