Solve the following systems of equations:
11x+15y+23=0
7x-2y-20=0
Answers
Given : 11x + 15y + 23 = 0
7x - 2y - 20 = 0
Solution :
Substitution method is used to solve this Linear pair of Equations:
Given , pair of system of equation is
11x + 15y + 23 = 0
11x + 15y = - 23……. (1)
7x - 2y - 20 = 0
7x - 2y = 20 ………. (2)
From eq (2), we have
-2y = (- 7x + 20)
2y = 7x - 20
y = (7x - 20)/2 ………..(3)
On Substituting the value of y in equation (1) we obtain ,
11x + 15y = - 23
11x + 15(7x - 20)/2 = - 23
11x + (105x - 300)/2 = - 23
(11x × 2 + 105x - 300)/2 = - 23
22x + 105x - 300 = - 23 × 2
22x + 105x - 300 = - 46
22x + 105x = - 46 + 300
127x = 254
x = 254/127
x = 2
Now , on putting x = 2 in the eq (3), we obtain :
y = (7x - 20)/2
y = (7 × 2 - 20)/2
y = (14 - 20)/2
y = - 6/2
y = - 3
Hence the solution of the given system of equation is x = 2 and y = - 3 .
Hope this answer will help you…
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Step-by-step explanation:
11x + 15y + 23 = 0 ---------------------(1)
7x - 2y - 20 = 0 -------------------(2)
2y = 7x - 20
y = 7x/2 - 10 put in equation (1)
11x + 105x/2 -150 + 23 = 0
127x/2 - 127 = 0
x = 2 put in equation (2)
14 - 2y - 20 = 0
y = -3