Question

Solve the equation 2z + 3 = 7 using trial and error method.
( 3 marks )

Answer 1

Solution:
The given equation 2z + 3 = 7
LHS: 2z + 3 (0.5 marks)
RHS: 7 (0.5 marks)
Solution of the equation is the value of z for which the LHS and RHS are equal.

Value of z	LHS (2z + 3)	RHS (7)	LHS = RHS (Yes or No)
1	$(2\times 1)+3=2+3=5$	7	$5\ne 7$, No
2	$(2\times 2)+3=4+3=7$	7	7 = 7, Yes
3	$(2\times 3)+3=6+3=9$	7	$9\ne 7$, No
4	$(2\times 4)+3=8+3=11$	7	$11\ne 7$, No

(2 marks)
Thus, the solution of equation 2z + 3=7 , is z=2.