Which is the best first step when solving the following system of equations?
x+y=3
4x-y=7
a multiply the first equation by 4.
b add the first equation to the second equation.
c multiply the second equation by negative 1.

option B. add the first equation the second, is the answer

using elimination method,

x + y = 3(1)

4x - y = 7(2)

once you add (1) and (2), the 'y' terms get cancelled, and you get,

5x = 10

x = 10/5

= 2

i think asking google will you get the answer to that question

option c) graph of line going through 1, 4 and 3, 10

step-by-step explanation:

let y equal to margo's coin collection

let x equal to number of years

at the begining x=0, y=1 → point=(x,y)→point=(0,1)

she adds 3 coins per year, then y=1+3x

at x=1, y=1+3(1)=1+3→y=4→point=(x,y)→point=(1,4)

at x=3, y=1+3(3)=1+9→y=10→point=(x,y)→point=(3,10)

the graph of line going through (1, 4) and (3, 10), then the option c is the correct.