You want to eliminate one of the terms (x or y) in one of the equations so you can solve for the other variable. You have to multiply by the opposite number of the coefficient to be able to eliminate the term in the other equation. If the x coefficient is 2, then you have to multiply the entire other equation by -2. If the y coefficient is -5, then you have to multiply the entire other equation by 5.
10)
-4x + 9y= 9
x - 3y= -6
STEP 1:
multiply the bottom equation by 4
4(x- 3y)= 4(-6)
4x - 12y= -24
STEP 2:
add the top equation and the equation from step 2
-4x + 9y= 9
4x - 12y= -24
the x term cancels out
-3y= 15
divide both sides by -3
y= -5
STEP 2:
substitute the y value in either original equation to solve for x
x - 3y= -6
x - 3(-5)= -6
x + 15= -6
subtract 15 from both sides
x= -21
ANSWER: x= -21; y= -5
____________________
12)
-7x + y= -19
-2x + 3y= -19
STEP 1:
multiply the top equation by -3 to eliminate the y term and to solve for x
-3(-7x + y)= -3(-19)
21x - 3y= 57
STEP 2:
add the bottom equation and the equation from step 2 to solve for x
-2x + 3y= -19
21x - 3y= 57
the y term cancels out
19x= 38
divide both sides by 19
x= 2
STEP 3:
substitute the x value in step 2 to solve for y; you can use either original equation
-7x + y= -19
-7(2) + y= -19
-14 + y= -19
add 14 to both sides
y= -5
ANSWER: x= 2; y=-5
Hope this helps! :)
Let Lynette has originally candies in hand = x
She gave half to her son means x/2 given to son.
2 candies gave to daughter and left with 4.
x - x/2 - 2 = 4
adding 2 both sides
x - x/2 - 2 + 2 = 4 + 2
x - x/2 = 6
x /2 = 6
x = 12
Means she have 12 candies originally : Answer
Hope it will help :)
1,2,3,4 are the domain. The x column is always the domain.
Multiply the money earned on the first day ($35.20) by 1/4.
= 35.20 * 1/4
multiply numerators
= (35.20 * 1)/4
=35.20/4
divide
= $8.80
ANSWER: $8.80 was used to buy more supplies
Hope this helps! :)
Let's assume
x represent the number of trips that the larger truck makes
so, we are given
If the smaller truck makes 18 more trips than the larger
so,
number of trips for larger truck =x
number of trips for smaller truck =x+18
The capacities of two trucks are 3 tons and 4 tons respectively
so, capacity of smaller truck per trip =3 tons / trip
total ton carried by smaller truck = (number of trips for smaller truck)*(capacity of smaller truck per trip)
now, we can plug values
total ton carried by smaller truck =3*(x+18)
total ton carried by larger truck = (number of trips for larger truck)*(capacity of larger truck per trip)
total ton carried by larger truck =4x
it can deliver 12 more tons of freight than the larger
so, we get
we can move 4x on left side
we get
...............Answer
