Forming Equations
I think of a number.
I multiply the number by 3 and then add 5.
The answer is 29.
3x + 5 = 29
x = 8
Solve the equation for a
a+5=12
a = 7
Solve for x:
2x+5=15
x = 5
Solve for x:
2x + 3 = 11
x = 4
I think of a number.
I divide the number by 2 and then add 1.
The answer is 7.
x/2 + 1 = 7
x = 12
Solve the equation for b
4b=20
b = 5
Solve for y:
3y−4=20
y = 8
Solve for x:
3x − 7 = 2x + 5
x = 12
Michael is x years old.
Jenny is twice as old as Michael.
The sum of their ages is 57.
2x + x = 57
x = 19
Solve the equation for c.
c/3=7
c = 21
Solve for z:
z/2 + 7 = 18
z = 22
Solve for x:
4(x−2) = 2x + 6
x = 7
Fiona is x years old.
Thomas is 3 years older than Fiona. Cara is twice as old as Fiona. The sum of their ages is 51.
x + (3+x) + 2x = 51
x = 12
Fiona: x = 12 years.
Thomas: (3+x) --> 3+12 = 15 years.
Cara: 2x --> 2(12) = 24 years.
Solve the system of linear equations by substitution.
−2d = 14
d = -14
Solve for a:
−5a+9=−16
a = 5
Solve for x:
5(2x+3) = 3(x+4) + 2
x = -1/7
Billy has x pounds.
Liam has twice as much money as Billy.
Nicola has three times as much money as Liam.
The total amount of money they have is $180
x + 2x + 3(2x) = $180
x = 20
Billy: 20 pounds.
Liam: 2x --> 2(20) = 40 pounds.
Nicola: 6x --> 6(20) = 120 pounds.
Solve the system of linear equations by substitution.
1/4 e = 6
e = 24
Solve for b:
2b/3 − 6 = 4
b = 15
Solve for x:
3(2x−4) + 5 = 2(x+6) − 7
x = 3