set up a table as shown below:
wire assembly test
super 5 6 2
deluxe 3 4 1
regular 2 3 1
total 690 910 280
let x represent number of super television sets.
let y represent number of deluxe television sets.
let z represent number of regular television sets.
your constraint equations are:
5x + 3y + 2z = 690 (equation 1)
6x + 4y + 3z = 910 (equation 2)
2x + y + z = 280 (equation 3)
these are 3 simultaneous equations in 3 unknowns that have to be solved simultaneously.
multiply both sides of the equation 1 by 3 and both sides of equation 2 by 2 to get:
15x + 9y + 6z = 2070 (equation 1 * 3)
12x + 8y + 6z = 1820 (equation 2 * 2)
subtract equation 2 * 2 from equation 1 * 3 to get:
3x + y = 250 (equation 4)
leave equation 2 as is and multiply equation 3 by 3 to get:
6x + 4y + 3z = 910 (equation 2)
6x + 3y + 3z = 840 (equation 3 * 3)
subtract equation 3 * 3 from equation 2 to get:
y = 70 (equation 5)
you are left with equations 4 and 5 as shown below:
3x + y = 250 (equation 4)
y = 70 (equation 5)
replace y with 70 in equation 4 to get:
3x + 70 = 250
subtract 70 from both sides of this equation to get:
3x = 180
divide both sides of this equation by 3 to get:
x = 60
so far you have x = 60 and y = 70
go back to any of the original equations and replace x with 60 and y with 70 and solve for z.
we'll use equation 1.
start with:
5x + 3y + 2z = 690 (equation 1)
replace x with 60 and y with 70 to get:
5*60 + 3*70) + 2z = 690
simplify to get:
300 + 210 + 2z = 690
combine like terms to get:
510 + 2z = 690
subtract 510 from both sides of the equation to get:
2z = 690 - 510
simplify to get:
2z = 180
divide both sides of the equation by 2 to get:
z = 90
now you have:
x = 60
y = 70
z = 90
replace x,y,z with 60,70,90 in all 3 equations and they should all be true.
start with:
5x + 3y + 2z = 690 (equation 1)
6x + 4y + 3z = 910 (equation 2)
2x + y + z = 280 (equation 3)
replace x with 60 and y with 70 and z with 90 to get:
5*60 + 3*70 + 2*90 = 690 (equation 1)
6*60 + 4*70 + 3*90 = 910 (equation 2)
2*60 + 70 + 90 = 280 (equation 3)
simplify to get:
300 + + 210 + 180 = 690 (equation 1)
360 + 280 + 270 = 910 (equation 2)
120 + 70 + 90 = 280 (equation 3)
combine like terms to get:
690 = 690 (equation 1)
910 = 910 (equation 2)
280 = 280 (equation 3)
all three equations are true when x = 60 and y = 70 and z = 90, therefore the solution is correct.
since x represents the number of super televisions and y represents the number of deluxe televisions and z represents the number of regular televisions, ....
the company should make 690 super, 910 deluxe, and 280 regular television so that they can utilize all the available resources.