Math, please help! thank you :)

Please explain! i don't understand thank you so much.(:
The temperature in San Diego is 86° Fahrenheit.



What is the approximate equivalent temperature in


Celsius? Use: F = 9/5C + 32


A. 16º C




B. 30º C


C. 66º C


D. 97º C

Firstly, do you understand what F and C stands for in the equation they've given you?

F = 9/5C + 32

F stands for Fahrenheit, C stands for Celsius.

They've given you F (86°), so all you have to do is substitute this value into the equation, then rearrange the equation to make C the subject. I'll show you :) :

Remember, in rearranging the equation, what you do to one side you do to the other.
86 = 9/5*C + 32 [take away 32 from both sides]
= 54 = 9/5*C [times both sides by 5 to get rid of the 5 on the right hand side]
= 270 = 9*C [divide both sides by 9 to get C on its own]
= 30 = C

Therefore the approximate equivalent temperature in Celsius in San Diego is 30°C. Hope that helped! :)

F = 9/5C + 32

that can be written as

F - 32 = 9/5C
(F - 32) / (9/5) = C
(F - 32) * (5/9) = C

If you want to calculate C from F, you have to put F in that formula

C = (86 - 32) * (5/9)
C = 54 * (5/9)
C = 270 / 9
C = 30

F = 9/5C +32

F = 1.8C +32

86 = 1.8C +32

86-32 = 54 = 1.8C

C = 54 /1.8 = 540/18 = 30 DEGREES C ANSWER

F = (9/5) C + 32
86 = (9/5) C + 32
54 = (9/5) C
30 = C

B

30

5*(86-32)/9 = c = 30

answer is B