Answer:
135.2857142857143
Step-by-step explanation:
its right?
3x - 3y + 2z = 7
3x + 1y - 3z = -5 ⇒ 6x - 2y - 1z = 2 ⇒ 42x - 14y - 7z = 14
7x - 1y - 2z = 0 ⇒ 7x - 1y - 2z = 0 ⇒ <u>42x - 6y - 12z = 0 </u>
-20y - 19z = 14
-20y + 20y - 19z = 14 + 20y
<u /> <u>-19z</u> = <u>14 + 20y</u>
-19 -19
z = -14/19 - 1 1/19y
3x - 3y + 2(-14/19 - 1 1/19y) = 7
3x - 3y - 1 9/19 - 2 2/19y = 7
3x - 5 2/19y - 1 9/19 = 7
<u> +1 9/19 +1 9/19 </u>
3x - 5 2/19y = 8 9/19
3x - 3x - 5 2/19y = 8 9/19 - 3x
<u /> <u>-5 2/19y</u> = <u>8 9/19 - 3x</u>
-5 2/19 -5 2/19
y = -1 64/97 + 57/97x
3x - 3(-1 64/97 + 57/97x) + 2(-14/19 - 1 1/19y) = 7
3x + 4 95/97 + 1 74/97x - 1 9/19 - 2 2/19y = 7
4 74/97x - 2 2/19y + 3.5056972328 = 7
<u> -3.5056972328 -3.5056972328</u>
4 74/97x - 2 2/19y = 3.494302767
4 74/97x + 2 2/19y - 2 2/19y = 3.494302767 + 22/19y
<u>4 74/97x</u> = <u>3.494302767 + 2 2/19</u>
4 74/97 4 74/97
x = 0.7336523126 + 0.4420141262y
3(0.733652316 + 0.4420141262y) - 3(-1 64/97 + 57/97x) + 2(-14/19 - 1 1/19y)=7
2.200956948 + 1.326042379y + 4 95/97 - 1 74/97x - 1 9/19 - 2 2/19y = 7 -1 74/97x - 0.7792207789y + 5.706654181 = 7
<u> -5.706654181 -5.70665418</u>
-1 74/97x - 0.7792207789y = 1.293345820
(x, y, z) = (0.733652316 + 0.4420141262, -1 64/97 + 57/97x, -14/19 - 1 1/19y)
In a word problem, it might not be clear which operation the problem is asking you to do. But, 3 key words from which you know the problem is asking you to add are: increase, together, and gained. Though these are not all of them, these are some of the (arguably) most important ones.
