Grade 7 2nd Quarter Lesson

1. Evaluation of Algebraic
Expression M7AL-IIc-4

2. REVIEW: Evaluate the
ff.:
Given: x = 5, y = 3, z = -2
1.) 3 (2x + y)
2.) z4 – 2y
2

3. Hanging Question
The costs of a pack of potato
chips, a can of soft drinks, and a
pack of biscuits are P12, P18
and P25, respectively. Vincent
wants to buy x packs of potato
chips, y can of soft drinks, and z
packs of biscuits.
Find the total cost if he buys 4
packs of potato chips, 6 cans of

4. Activity
Directions: A square is a “magic
square” if the sums of the
numbers in a row, column, and
diagonal are the same. This
special sum is called the magic
constant.
Find the magic constant if
x= 2, y = 4, and z = 1.

5. Find the magic constant if
x= 2, y = 4, and z = 1.
x xy + 1 (y + z) - z
xy - z y + z x + 1
x + y x - z xy

6. Discussion:
To evaluate algebraic expression is to find
its numerical value by substituting the
given set of numbers in place of letters or
variables.
Steps to follow in evaluating algebraic
expressions.
 Substitute the given values for each
variable.
 Simplify first the expressions within the
grouping symbols.
 Simplify the expressions with exponents.

7. Examples:
Evaluate using the given values.
a = 1, b = 2, c= 3, x = -3, y= -2, z = -1.
1.) 2a + b – c = 3
2.) 16 (x – y ) + 12 (a + z) = -16
3.) 3c – 5z2 = 4
4.) ab/y2 = 1/2
5.) 3a/5 - 7b = -67/5 or -13 2/5

8. Application:
1.) Evaluate 3x – 2y + 5 when x = 2 and y = 4
2.) Evaluate 4( a – 3) + 3 ( a + 2) when a = 5
3.) Evaluate ( 5y÷ 3 ) + 2 ( y – 6 ) when y = 9
4.) Evaluate 2a(4x2)
3y when a = 1, x= -3 and y = 3.
5.) Evaluate 3a – 7b
2a + 6b if a =1 and b = 2
6.) Evaluate 6 –b ( y + z)
if a = 1, b=2, y = -1 and z = 0

9. Evaluation:
Direction: Choose the letter of the correct answer.
Evaluate the value of each expression if:
a = 1, b= -1 , c = 2, x= -2, y =1, z = 0
1.) 8ab + 3bc – 12 a.) 0 b.) 22 c.) 26 d.) -26
2.) 3xy + 15 a.) 0 b.) 14 c.) 16 d.) -16
15
3.) 3x3 + 7y – 4z a.) 8 b.) 17 c.) -17 d.) -8
4.) bc + c + 2 a.) 0 b.) 2 c.) 4 d.) 6
2 xy ay
5.) 2 ( x – 8) + x a.) 0 b.) -2 c.) -16 d.) -22

10. Assignment
1.)Evaluate (a + b) – 24 if a = 3 and b = 2
2.) Evaluate 2a + b + c2
if a= 9, b= 13 and c = 6
3.) Evaluate
if a = -2, b = 3, c = -1
4.) Evaluate 3a + [ { 4 (b + c2) } – (b – a) ]
if a = -2, b = 3, c = -1
5.) Evaluate {2 ( 3 – b2)} – (c – b)
if b = -1 and c = -2