Download 1.1 Solving One step Equations

1.1 SOLVING ONE STEP
EQUATIONS
WHAT WE WILL LEARN
• Solve linear equations using addition and
subtraction
• Solve linear equations using multiplication and
division
• Use linear equations to solve real-life problems
EX. 1 SOLVING BY
ADDING/SUBTRACTING
• Solve each
equation
• Do the opposite
• X – 3 = -5
• +3 +3
• X = -2
• .9 = y + 2.8
• -2.8
-2.8
• -1.9 = y
• Same sign, add and
keep sign
• Different sign,
subtract and keep
sign of bigger
number
YOUR PRACTICE
• Solve
• n + 3 = -7
•
-3 -3
• n = -10
• Solve
• -6.5 = p + 3.9
• -3.9
-3.9
• -10.4 = p
EX. 2 SOLVE BY MULTIPLY/DIVIDE
• Solve each equation
• 1.3z = 5.2
• Divide by 1.3
•
1.3𝑧
1.3
5.2
1.3
=
• z=4
• -
𝑛
5
= −3
• Multiply by -5
• Always want letter to
be positive
• −5
−
• n = 15
𝑛
5
= −3 −5
• When multiplying or
dividing two
negatives or two
positives, the answer
will be positive
• When multiplying or
dividing a negative
and a positive, the
answer will be
negative
YOUR PRACTICE
• Solve
•
𝑦
3
• Solve
• .05w = 1.4
= −6
• 3
𝑦
3
• y = -18
= −6 3
•
.05𝑤
.05
=
• w = 28
1.4
.05
EXS. 3 AND 4 STORY PROBLEMS
• A discounted amusement park ticket costs $12.95 less than the
original price p. You paid $44. Write and solve an equation to
find the original price.
• Ticket = original – 12.95
• 44 = p – 12.95
• +12.95 +12.95
• 56.95 = p
• The temperature at 5 pm is 20 F. The temperature at 10 pm is 5 F. How many degrees did the temperature fall?
• t = 20 – (-5)
• t = 25