Answer:
im not really smart lol
Step-by-step explanation:
Answer:
4
Step-by-step explanation:
7+(-14)+(-6)+13+4
7+(-20)+13+4
(-13)+13+4
0+4
4
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
Let p = number of pennies.
Let n = number of nickels.
We are given that n= 2p and the total value is $8.80.
We know that a penny = $0.01 and that a nickel = $0.05.
So $0.01p + $0.05n = $8.80.
Substitute 2p for n:
$0.01p + $0.05*2p = $8.80
$0.01p + $0.10p = $8.80
$0.11p = $8.80
p = 80
So n = 2p = 2*80 = 160
Thus there are 80 pennies ($0.8) and 160 nickels ($8.00). The value of all the coins is $8.80.
6x + 7y = 59...multiply by -4
4x + 5y = 41...multiply by 6