Everything Maths Grade 10

SOLUTION

Step 1: Isolate the required variable

We are asked to isolate the height, so we must rearrange the equation withhon one side of the equals sign
and the rest of the variables on the other.

A=

1

2

bh

2 A=bh

2 A

b

=h

Step 2: Write the final answer

The height of a triangle is given by:h=

2 A

b

Worked example 16: Solving literal equations

QUESTION

Given the formula:

h=R

H

R+r^2

makeRthe subject of the formula.

SOLUTION

Step 1: Isolate the required variable

h

(

R+r^2

)

=RH

hR+hr^2 =HR

hr^2 =HRhR

hr^2 =R(Hh)

)R=

hr^2

Hh

Exercise 4 – 5:

1.Solve forxin the following formula: 2 x+ 4y= 2.

2.Makeathe subject of the formula:s=ut+^12 at^2.

3.Solve forn:pV=nRT.

4.Makexthe subject of the formula:

1

b

+

2 b

x

= 2.

5.Solve forr:V=r^2 h.

6.Solve forh:E=

hc



.

Chapter 4. Equations and inequalities 95