x + 2 y = 0 is the equation that has the value (1.8, -0.9).
<u>Step-by-step explanation:</u>
The solution is (1.8,-0.9) and the given equations are
x-2y= 4....... 1
4x+5y= 8.....2
6x-5y=15.....3
x+2y=0........4
Substitute the solution in all the equations and equate the resulting values.
∴ Substitute (1.8, -0.9) in equation 1.
1.8-2(-0.9) = 4.
1.8 + 1.8 = 4.
3.6 ≠ 4.
Substitute (1.8, -0.9) in equation 2.
4(1.8)+5(-0.9)=8
7.2-4.5=8.
2.7≠8.
Substitute (1.8, -0.9) in equation 3.
6(1.8)-5(-0.9)=15.
10.8 + 4.5=15
15.3≠15.
Substitute (1.8, -0.9) in equation 4.
1.8+2(-0.9)=0.
1.8-1.8=0.
0=0.
∴x + 2 y = 0 is the equation that has the value (1.8, -0.9).
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