Word Problems
Write an equation for this story: The initial freshman class at a college is 10% smaller than last year’s class. But then during the first week of classes, 20 more students enroll. There are then 830 students in the freshman class.
0.9x + 20 = 830
4+b=7
b=3
6x-2x=24
x=6
a · 3 = -30
a=____
a=-10
Is this an expression or equation?
2y+6x+12+4y-18y
Expression
Write an equation for this story: A store reduces the price of a computer by $20. Then during a 10% off sale, a customer pays $830.
0.9(x − 20) = 830
-10+x=4
x=14
2x+5=21
x=8
b. -9 · b=45
b = ____
b=-5
What makes an equation different than an expression?
It has an equal sign.
Diego tried to solve the equation 1/3(x+15)=3 What was his mistake?
1/3(x+15)=3
1/3x=-12
x=-4
He subtracted 15 before multiplying by 1/3
4x=20
x=5
3b-4=11
b=5
-89 · 12 = c
c=____
c = -1,068
List the FOUR steps to solve an equation in the correct order.
1. Isolate Variable
2. Inverse Operations
3. Balance Equation
4. Plug-in
Miss Polis buys sweet tea every school day to wake her up in the morning. On Friday she decides to buy a bagel that cost $3.50. At the end of the week she spent 19.50. Write an equation to represent this situation.
5x+3.50=19.50
x/2=5
x=10
2(3x+1)=14
x=2
d · 88 = -88,000
d=______
d=-1000
Write an expression to show seven decreased by a number, x
7-x
Miss Polis buys sweet tea every school day to wake her up in the morning. On Friday she decides to buy a bagel that cost $3.50. At the end of the week she spent 19.50. What is the cost of sweet tea?
$3.20
0.3r=2.1
r=7
2(x+2x)=36
x=6
3(r+3)=27
r=_____
r=6
Write an equation for this story.
Tom has 2 oranges and some strawberries. In all, he has 7 pieces of fruit. How many strawberries does he have?
2+s=7