Which graph represents a reflection of f(x)=1/10(10)x accross the y axis

Can someone check if i did this correct. it’s number 4 if you’re wondering.

Agroup of three friends order a combo meal which includes two slices of pizza and a drink each drink is priced at $2.50 the combined total of $31.50 how much is the cost of a slice of pizza

Find the solution to this system 2,1 1,-2 1,2 -1,2