The answer is: [A]: " 20a − 5b − 9 " .
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Explanation:
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(12a <span>+ 7b) + (−6a − 9) + (14a − 12b) =
12a </span><span>+ 7b + 1(−6a − 9) + 1(14a − 12b) =
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12a + 7b + (1*-6a) + (1*-9) + (1*14a) + (1* -12b) =
12a + 7b − 6a − 9 + 14a − 12b = ?
Combine the "like terms:
12a − 6a + 14a = 20a ;
7b − 12b = - 5b ;
and then we have "-9" ;
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So, write as: " 20a − 5b − 9 " ; which is: Answer choice: [A].
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Answer:
i dont know i just want points
Step-by-step explanation:
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Answer:
Given System of equation:
x-y =6 .....,[1]
2x-3z = 16 ......[2]
2y+z = 4 .......[3]
Rewrite the equation [1] as
y = x - 6 .......[4]
Substitute the value of [4] in [3], we get

Using distributive property on LHS ( i.e,
)
then, we have
2x - 12 +z =4
Add 12 to both sides of an equation:
2x-12+z+12=4+12
Simplify:
2x +z = 16 .......[5]
On substituting equation [2] in [5] we get;
2x+z=2x -3z
or
z = -3z
Add 3z both sides of an equation:
z+3z = -3z+3z
4z = 0
Simplify:
z = 0
Substitute the value of z = 0 in [2] to solve for x;

or
2x = 16
Divide by 2 both sides of an equation:

Simplify:
x= 8
Substitute the value of x =8 in equation [4] to solve for y;
y = 8-6 = 2
or
y = 2
Therefore, the solution for the given system of equation is; x = 8 , y = 2 and z =0