Creating Equations
Jenny has 7 marbles and Kenny has 5. How many do they have together? Let x be the total number of marbles.
x = 7 + 5
x = 12
2x -1 = 3
Solve for x.
x = 2
4x + 1 = 2x + 3
Solve for x.
x = 1
x + 3 > 7
Solve the inequality.
x > 4
x + y = 4
x - y = 6
x = 5
y = -1
(5,-1)
A number x is squared, tripled, halved and then increased by 12. After all this the equation equals 6.
3x2/2 + 12 = 6
6x +18 = 24
Solve for x.
x = 1
2x - 4 = x + 6
Solve for x.
x = 10
2x < -8
Solve the inequality.
x < -4
2x + y = 4
8x - y = 6
x = 1
y = 2
(1,2)
You want to buy x bags of chips. Each bag is 2 dollars, and you have 24 dollars to spend.
2x = 24
(1/7) x +7 = 9
Solve for x.
x = 14
-2(x + 6) = 2
Solve for x.
x = -7
3x - 5 > x - 3
Solve the inequality.
x > 1
4x + y = 6
-2x - y = 12
x = 9
y = - 30
(9, -30)
Helen has 2 inches of hair cut off each time she goes to the hair salon. If h equals the length of hair before she cuts it and c equals the length of hair after she cuts it, which equation would you use to find the length of Helen's hair after she visit the hair salon?
c = h - 2
(2/3)x - 1 = 5
Solve for x.
x = 9
6x - 5 = x/2
Solve for x.
x = 10/11
x/3 < 2x - 4
Solve the inequality.
x > 12/5
3x + y = 8
x + 2y = 1
x = 3
y = -1
(3,-1)
Jenny, Kenny, and Penny together have 51 marbles. Kenny has double as many marbles as Jenny has, and Penny has 12. How many does Jenny have?
n + 2n + 12 = 51
3n + 12 = 51
(7/5)x - 12 = -5
Solve for x
x = 5
3x2 + 2 = 29
Solve for x.
x = 3
2x2 - 5 < 21
Solve the inequality.
x < sqrt(13)
2x + 4y = 8
-5x + 4y = 1
x = 1
y = 3/2
(1,3/2)