Writing Equations
Two less than twice a number is six.
2x - 2 = 6
w + 4 = -8
w = -12
d/-4+4=12
d = -32
0.1/2=0.5/x
x = 10
Solve for b
A=b*h
b=A/h
1/4(r+10)=r-4
-7t = 49
t = -7
4n - 12 = 12 - 4n
n = 3
4/(b-2)=4/12
b = 14
Solve for w:
2w-y=7w-2
w=(2-y)/5
A potted tree weighs 21 pounds. The pot weighs 3 pounds. If w represents the weight of the tree without the pot, write an equation to find the weight of the tree without the pot.
3 + w = 21
8x = 96
x = 12
2(3a + 7) = -4(3 - 2a)
a = 13
(a-8)/12=(2a+5)/3
a = -4
A bus leaves town A traveling toward town B. At the same time a car leaves town B traveling toward town A. The speed of the bus is 50 miles per hour and the speed of the car is 60 miles per hour. The distance between the two towns is 1980 miles. How many hours until the bus and car meet?
18 hours
A cliff on the seashore is eroding at the rate of 17 centimeters per year. Write an equation to find the number of years in which the cliff will erode 85 centimeters.
17n=85
8 - 5w = -37
w = 9
8x + 12 = 4 (3 + 2x)
Infinitely Many Solutions
State the percent of change.
original: 25
new: 28
12% increase
Bill has invested in two savings accounts. One earns 5% and the other earns 8%. The total amount invested is $2,100 and the total interest earned for the year is $153. How much is invested in each account?
5% account: 500
8% account: 1600
Michael is collecting sea glass from the beach. He begins with 14 pieces in his collection and adds 3 new pieces per day. Write an equation to help him determine how many days it will take Michael to have 80 pieces of sea glass in his collection.
80 = 14 + 3x
Sharon went bowling with her friends. She paid $3 to rent her shoes and then $3.75 for each game of bowling. She spent a total of $18. How many games did she play?
4 games
UPS charges $7 for the first pound, and $0.20 for each additional pound. FedEx charges $5 for the first pound and $0.30 for each additional pound. How many pounds, p, will it take for UPS and FedEx to cost the same?
20 pounds
The team's ratio of games won to games played is 3 to 8. If the team played 56 games, how many did they win?
21 games
The pressure exerted on an object is calculated by the formula P=F/A, where P is the pressure, F is the force, and A is the surface area of the object. Water shooting down from a hose has a pressure of 75 pounds per square inch (psi). Suppose the surface area covered by the direct hose spray is 0.442 square inches. Solve the equation for F and find the force of the spray.
33.15 pounds.