Answer :
Answer:
none
Step-by-step explanation
A. 2x-3y=2
B. 4x-y=10
Okay.
2(7)-3(4)=2 ⇒ 14-12=2
not correct, 4(7)-(4)=10 ⇒ 28-4=24
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2(5)-3(2)= 10-6=4 not 2, incorrect
4(5)-2=10 ⇒20-2=18 incorrect.
Answer A, B, C and D are incorrect. They didn't give you the correct equations or answers. Heres why
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A. 2x-3y=2
B. 4x-y=10
1. neither equation contains an isolated variable (aka, y=x+2, y is the isolated variable). However, we can isolate -y in equation B by subtracting -4x on both sides.
Ending up with -y=10-4x
Now I like to change -y into y and it's very easy. All you need to do is:
[tex]\frac{-y=10-4x}{-y}[/tex] Remember: [tex]\frac{neg}{neg}=pos, \frac{neg}{pos}=neg, \frac{pos}{neg}=neg,\frac{pos}{pos} =pos[/tex]
Ending up with y=-10+4x
2.Now, we can plug the expression (a phrase) -10+4x into equation A as a substitute for y and solve for x.
[tex]2x-3(-10+4x)=2\\ 2x+30-12x=2\\ -10x+30=2\\ -10x+30-30=2-30\\ -10x=-28\\ \frac{-10x}{-10x} =\frac{28}{-10x}\\ x=-2.8[/tex]
3. Solve for y.
[tex]2(-2.8)-3y=2\\ -5.6-3y=2\\ -5.6+5.6-3y=2+5.6\\ 3y=7.6\\ \frac{-3y}{-3y}=\frac{7.6}{-3y} \\ y=-2.5333333[/tex]
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No solution
3≠5
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Infinitely Many Solutions
3=3