Ihave to evalaute expressions can someone tell me which whay is the correct way.

15+ 20 ÷ 5
Is
15 + 4= 19 or 5 ÷ 5=9

210-5 x 30
Is it
210-150=60 or 205 x30=61590

Have you heard of BEDMAS?

it shows the correct order of operation in arithmetic
B-brackets first
E-exponents
D
M ...Division and Multiplication in the order they come
A
S ... Addition and Subraction in the order they come

so for your first one it is
15 + (20 ÷ 5)
=15 + 4
=19

thanks I got the next one
210-150=60