Which of these strategies would eliminate a variable in the system of equations?

( 6x + 5y = 1

16x - 5y = 7

Choose all answers that apply:

B) Subtract the bottom equation from the top equation.

C) Add the equations.

Step-by-step explanation:

Let us analyze each of the options to see which one of them work.

A) Multiply the top equation by 7, then subtract the bottom equation from the top equation.

Multiplying the top equation by 7 gives:

7 * (16x + 5y) = (1 * 7)

112x + 35y = 7

Then, subtracting the bottom equation from this:

 112x + 35y = 7

-  (16x - 5y = 7)

=> 112x + 35y - 16x + 5y = 7 - 7

112x - 16x + 35y + 5y = 0

96x + 40y = 0

This method didn't eliminate any variable, so it didn't work for us.

B) Subtract the bottom equation from the top equation

This will yield:

  16x + 5y = 1

- (16x - 5y = 7)

=> 16x + 5y - 16x + 5y = 1 - 7

16x - 16x + 5y + 5y = -6

0x + 10y = -6

10y = -6

y = -6 / 10

Hence, one variable has been eliminated. It works.

C) Add the equations

This yields:

  16x + 5y = 1

+ 16x - 5y = 7

  32x + 0y = 8

  32x = 8

=>x = 8 / 32 = 1 / 4

This method works since one variable has been eliminated.

constant acceleration- a

constant velocity- c

no velocity or acceleration- b

explanation:

for body moving with a constant acceleration, the rate of change of displacement changes over time. this is proven by the increasing gradient of the curve (a) against time.

a body that is moving at constant velocity covers equal distances over equal periods of time, thus the straight line with a constant gradient c.

a stationary body   covers no displacement as time elapses. thus the flat line with   zero gradient.

the answer is c. 23/3