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! :)
Answer:
The linear function that discribes the size of the population in function of the t in years is p = 700t - 1,397,300
Step-by-step explanation:
A linear function is defined by a line, so in order to determine the linear function we can use the two points that were given to us to create a line equation and use that as our linear function. The points given to us were (2009; 9000) and (2014; 12500), in this case the year is our value of "x" and the size of the population is our value of "y". The first step is to find the slope of the line which is given by:
m = (y2 - y1)/(x2 - x1)
m = (12500 -9000)/(2014 - 2009) = 3500/5 = 700
Then we can use the slope and the first point to build the equation:
p - 9000 = 700*(t - 2009)
p = 700t - 1406300 + 9000
p = 700t - 1397300
Let’s convert all their jumps into inches.
Breanna’s is already in inches (62)
Myquisha jumped 5 feet 4 inches
There are 12 inches in a foot, so
5 feet * 12 inches= 60 inches
Then add the 4 inches
60+4= 64
So Myquisha jumped 64 inches.
Ariana jumped 1 yard, 2 feet, 7 inches
1 yard is equal to 3 feet.
So, she jumped 5 feet 7 inches
12 inches in a foot, so
5*12=60 inches
Add the 7
60+7= 67 inches
So Breanna jumped 62, Myquisha 64 and Ariana 67
In order of shortest to longest:
Breanna, Myquisha, Ariana
B+25..... 2*25+50 ... 50+50=100
