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Given that x = -2, find the values of y and z for the simultaneous equations. x + y - z=-1 x - 2y + z=-7

Class: Form 1

Subject: Mathematics

Topic: Linear Equations

Lesson Summary

Given that x = -2, find the values of y and z for the simultaneous equations.

x + y - z=-1
x - 2y + z=-7



Text Answer


If x = -2
-2 + y – z = -1
Y – z = -1 + 2 y – z = 1 ……(1)

And -2 – 2y + z = -7
-2y + z = -7 + 2
-2y + z = -5 …….(2)

From (1) z = y – 1
Substitute in (2)
-2y + y – 1 = -5
-y = -5 + 1
-y = -4 y=4

Z = y – 1
Z = 4-1
Z = 3

Y = 4
Z = 3.


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