Of . 3x+4y+4z=4, 5x+7y+3z=5 4x+5y+7z=7

We'll label the equations to keep track of what we're doing

3x+4y+4z=4    A

5x+7y+3z=5    B

4x+5y+7z=7     C

Normally in Gaussian elimination we'd pick put a constant on each equation and combine to cancel out a variable in all but one.  But here we have an opportunity to make the coefficient 1 on our variables in at least one equation.  This is a pretty good thing to do when solving these by hand.

x + y + 3z = 3         D=C-A

-2x - 3y + z = -1     E=A-B

Let's eliminate x from two equations

-y + 7z = 5          F=2D+E

-y + 5z = 5         G=4D-C

Let's eliminate y

2z = 0               H=F-G

z = 0

-y + 7z = 5

y = -5

x + y + 3z  = 3

x - 5 + 0  = 3

x = 8

(x,y,z)=(8,-5,0)

Check:

3(8)+4(-5)+4(0) = 4, good

5(8)+7(-5)+3(0)=5, good

4(8)+5(-5)+7(0)=7, good

the answer is 5/3x+7/5y+7

answer: the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

step-by-step explanation:

the given rate of interest i= 85%

in calculating the monthly payment for a loan with an interest rate compounded monthly, the value of the interest rate per period we use in the formula must be in decimal form.

to convert it in decimal, we divide it by 100, we get

hence, the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.