Solve y=-x+2 and y=-2x-1 as a graph, substitution, or elimination?

(- 3, 5 )

Step-by-step explanation:

Given the 2 equations

y = - x + 2 → (1)

y = - 2x - 1 → (2)

Using substitution method.

Substitute y = - x + 2 into (2)

- x + 2 = - 2x - 1 ( add 2x to both sides )

x + 2 = - 1 ( subtract 2 from both sides )

x = - 3

Substitute x = - 3 into (1)

y = - (- 3) + 2 = 3 + 2 = 5

Solution is (- 3, 5 )

  about 5.6 days

step-by-step explanation:

we can fill the given information into the decay equation and solve for the value of t at which half the sample remains.

the half-life is about 5.6 days.