Answer:
One pair of jeans cost $35.
One sweatshirt cost $16.
Step-by-step explanation:
j = jeans
s = sweatshirts
5j + 2s = $207
3j + 4s = $169
System of equations. You now must choose to either cancel out "j" or "s".
I'm going to cancel out the "s".
In order to cancel out the "s" you must make the number in front of each s the same number, but opposite. Meaning one is negative, and the other is positive.
2s and 4s. You can get 2 to 4 by multiplying by 2. And you want it to be negative. So you'll be multiplying the ENTIRE top equation by -2.
-2(5j+2s=207)
-2 x 5j = -10j
-2 x 2s = -4s
-2 x 207 = -414.
Rewrite the equation.
-10j - 4s = -414.
3j + 4s = 169.
You can now cancel out the "s"'s by adding them together. -4 + 4 = 0.
Now, you must add the other numbers, both "j"s and both of the totals.
-10j + 3j = -7j.
-414 + 169 = -245.
Put those numbers back into the equation..
-7j = - 245.
Divide both sides by -7 to get j by itself.
j = 35; each pair of jeans is worth $35.
Now, solve for "s" by plugging the value of j (35) into either of the ORGINAL equations. (5j + 2s = $207 OR 3j + 4s = $169)
5j + 2s = 207.
5(35) + 2s = 207.
175 + 2s = 207
Subtract 175 from both sides.
2s = 32
Divide both sides by 2.
s = 16; each sweatshirt costs $16.
