In order to solve the following system equations by addition which of the following cool you do before adding the question so that one variable will be eliminated when you’re at them
2x-4y=5
6x-3y=10

y=-5/9 and x=25/18

Step-by-step explanation:

2x-4y=5

6x-3y=10

Multiple the top by -3

-6x+12y=-15

6x-3y=10

Add both equations

9y=-5

y=-5/9

Plug in y to any equation to find x

6x-3(-5/9)=10

6x+5/3=10

Multiple by 3

18x+5=30

18x=25

x=25/18

Watch out for negative signs

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.

answer: the four apples you took away.

step-by-step explanation: