9514 1404 393
Answer:
(x, y, z) = (-1, 0, -3)
Step-by-step explanation:
We notice that the coefficients of z are such that elimination of the z term from the equations is made easy.
Adding equations 1 and 2:
(2x -3y -2z) +(x +3y +2z) = (4) +(-7)
3x = -3
x = -1
Adding equations 2 and 3:
(x +3y +2z) +(-4x -4y -2z) = (-7) +(10)
-3x -y = 3
Substituting for x, we get ...
(-3)(-1) -y = 3
0 = y . . . . . . . . . . . add y-3 to both sides
Then z can be found from any equation. Substituting for x and y in the second equation gives ...
-1 +2z = -7
2z = -6 . . . . . add 1
z = -3 . . . . . .divide by 2
The solution is (x, y, z) = (-1, 0, -3).
Step-by-step explanation:
Wendy
-20 = x/2 + 7
-20 -7 = x/2 + 7 -7
-27 = x/2
-54 = x
x = -54
because it's math rule
Answer:
$12.80
Step-by-step explanation:
Sara bought 4 pounds of coffee.
Each pound (lb) costs $3.20
To find the total cost, multiply the cost per pound ($3.20) with the amount of pounds Sara is going to buy (4):
4 x 3.20 = $12.80
$12.80 would be the total cost before tax.
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