Simple linear equation

Simple linear equation Linear equation can be solved by using substitution method. Substitution method is used to solve equation for one or more variable. To find value of the variable , substitute the values one by one until the LHS = RHS.

Example 1 : If p takes the value 2 then find the value of p +10 Example 1 : If p takes the value 2 then find the value of p +10. Given: p = 2 To find: value of p + 10 Solution p + 10 Substitute p = 2 = 2 + 10 = 12

Example 2 : If y takes the value 25 then find the value of y - 20 Example 2 : If y takes the value 25 then find the value of y - 20. Given: y = 25 To find: value of y - 20 Solution y - 20 Substitute y = 25 = 25 - 20 = 5

If m + 4, find the value for m , to get sum 9. Solution Example 3 : If m + 4, find the value for m , to get sum 9. Solution Substitute the value for m , until you get the value 9. Is it 9 ? Yes / No m m + 4 Result 1 1 + 4 5 No 2 2 + 4 6 No 3 3 + 4 7 No 4 4 + 4 8 No 5 4 + 5 9 Yes Ans m = 5

For what is the value of z , 6z – 5 gives 13 ? Solution Example 4 : For what is the value of z , 6z – 5 gives 13 ? Solution Substitute the value for z , until you get the value 13. if z=1 6 z - 5 6 x 1 - 5 6 – 5 = 1 so if z=1, 6z-5 ≠ 13 if z=2 6 z - 5 6 x 2 - 5 12 – 5 = 7 so if z=2, 6z-5 ≠ 13 if z=3 6 z - 5 6 x 3 - 5 18 – 5 = 13 so if z=3, 6z-5 = 13 Ans z = 3

Try these If n = 3 , find the value of n +6 What is the value of x , if x- 5 = 2