You can roughly convert temperature in degrees Celsius to degrees

Fahrenheit by doubling the degrees Celsius and adding 30.
Draw a conversion graph up to 50 °C. Use your graph to estimate the
following:
a the temperature in °F equivalent to 25°C,
b the temperature in °C equivalent to 100 °F,
c the temperature in °F equivalent to 0°C,
d the temperature in °C equivalent to 200 °F

It is not possible to draw a graph on this site.

You can write this question as:

F = 2 C + 30

where

F = temperature [°F]

C = temperature [°C]

Draw a Cartesian coordinate system.

Mark the horizontal axis with C and the vertical axis with F

Now calculate:

F = 0

2 C + 30 = O

2 C = - 30

C = - 30 / 2 = - 15

and

C = 0

F = 2 • 0 + 30 = 30

In Cartesian coordinate system drav points:

C = - 15 , F = 0

( - 15 , 0 )

and

F = 30 , C = 0

Draw a straight line through these two points.

That is a conversion graph.

Read on graph:

25° C = 80° F

100°F = 35°C

0°C = 30°F

200°F = 85°C