7th Grade Math

222 Equations and Inequalities

Sometimes the coefficient of a term in a multiplication equation is a

rational number. If the coefficient is a decimal, divide each side by the

coefficient. If the coefficient is a fraction, multiply each side by the

reciprocal of the coefficient.

0.75x = 3.75 _^23 x = 4

_0.750.75x = _0.753.75 _ 32 · _^23 x = _ 23 · 4

x = 5 x = 6

Decimal Coefficients

Solve 16 = 0.25n. Check your solution.

16 = 0.25n Write the equation.

_0.25^16 = _0.250.25n Division Property of Equality

64 = n Simplify.

Check 16 = 0.25n Write the original equation.

16  0.25 · 64 Replace n with 64.

16 = 16 ✓ This sentence is true.

The solution is 64.

e. 6.4 = 0.8m f. -2.8p = 4.2 g. -4.7k = -10.81

ICE CREAM Jaya’s softball coach agreed to buy ice cream cones for

all of the team members. Ice cream cones are $2.40 each. How

many ice cream cones can the coach buy with $30?

Let n represent the number of ice cream cones the coach can buy.

2.4n = 30 Write the equation; $2.40 = 2.4.

_2.42.4n = _2.4^30 Division Property of Equality

n = 12.5 Simplify.

Since the number of ice cream cones must be a whole number,

there is enough money for 12 ice cream cones.

h. ICE CREAM Suppose the ice cream cones cost $2.80 each. How

many ice cream cones could the coach buy with $42?

Division

5.

0.75  3.75

• 3.75
  0

Real-World Link

Each year, over

1.5 billion gallons

of ice cream are

produced in the

United States.

RR

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