What are you going to
À To define a linear
equation with one
À To make a model to
state an equation
À To understand Solution
and Solution Set
Key Terms :
linear equation with
solution and Set
Think and discuss. A circus has 3 male and 3 female
tigers. a) If the keeper feeds 39 kg of meat to the tigers
each day and each tiger gets the same portion, what
is the weight of meat fed to each tiger everyday?
b) If each tiger eats m kg of meat everyday, and the
meat eaten by all tigers is 45 kg, write down an open
sentence related to the weight of meat eaten by all
tigers. How many kg of meat are eaten by six female
c) If a male tiger eats meat twice as much as a female
tiger, and the meat eaten by all tigers is 36 kg, how
many kilograms of meat are eaten by six male tigers?
In the tiger problems:
• If one tiger eats m kg, then the relation is 6m = 45.
• The value of m is unknown. Therefore, m is a variable. An open sentence
that uses the sign “=” is called an equation.
• If the highest power of the variable in an equation is 1, then that
equation is called a linear equation.
Mathematics for Junior High School – Year 7/
Consider the following equations. Determine which
ones are linear equations with one variable? Give the
a) p - 12 = 5
b) t + r = 28
c) h2 = 16
d) 2k – 3 = k + 7
Think and discuss. To celebrate the Independence
Day of Indonesia, students of “SMP Association” and
students of “SMP Reconciliation” held a competition
in the square of the district. They went to the square
of the district by car and bicycle. Students of “SMP
Association” needed three cars and six bicycles.
Students of “SMP Reconciliation” needed two cars
and seven bicycles.
The number of students in each car was the same.
If the total number of the students of those two
schools was 88,
(a) how many cars were used