Leila works mowing lawns and babysitting. She earns $8.30 an hour for mowing and $7.30 an hour for babysitting. How much will sh
1 answer:
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Answer:
C. x+y = 1 and -x-y = -1
Step-by-step explanation:
Remember that if a system of equations has an infinite number of solutions, then the resulting equation from using the first step of the elimination method would have no variables and would be true.
1) Let's try canceling out the equations in option C, x+y =-1 and -x-y =-1. Add the two equations together. (Work shown in attached picture.)
2) All of the terms cancel out with each other, leaving only a true statement of 0 = 0. Thus, option C is the answer.
Answer:
a ) y = 1 and x = -1
d) y = 5 and x = -1/2
Step-by-step explanation:
<h2><u>Substitution method</u></h2><h2><u>Question a</u></h2>y = x+ 2
y = 2x + 3
<em>we can make the first formula in terms of x , so we can place in into the second formula</em>
y = x + 2
x = y - 2
now put y - 2 where x is in the second equation
y = 2x + 3
y = 2(y - 2) + 3
y = 2y - 4 +3
now solve
4 - 3 = 2y -y
y = 1
since y = 1 we can find what x is by putting into the first formula
y = x +2
x = y - 2
x = (1) -2
x = -1
<h3><u>hence y = 1 and x = -1 </u></h3><h3><u /></h3><h2><u>Question d</u></h2>y = 2x + 6
y = 4 - 2x
<em>we can make the first formula in terms of x , so we can place in into the second formula</em>
y = 2x + 6
y - 6 = 2x
x = (y-6)/ 2
now place (y-6)/2 where x is in the second formula
y = 4 -2x
y = 4 - 2 ()
now solve
the multiplication by 2 and division by 2 are cancelled out
hence making the simplified equation as:
y = 4 - y + 6
2y = 4 + 6
2y = 10
y = 5
now place this into the first equation
y = 2x + 6
y - 6 = 2x
x = (y-6)/ 2
x = (5-6)/2
x = -1/2
<h3><u>hence y = 5 and x = -1/2</u></h3>