PLEASE HELP FOUR PROBLEMS SUBSTITUTION AND ELIMINATION ALGEBRA!!

1.
y=-7x+10
3x+2y=9

2.
12x-10y=2
-6x+7y=-1

3.
y=5x
8x-3y=35

4.
y=-2x+28
y=5x

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950

a

step-by-step explanation:

ok thats very interesting

they would have to work 32 hours.