Answer:
x=-2/3
Step-by-step explanation:
Answer:
Step 1
Step-by-step explanation:
Carly divided 7a by a when she should have divided 7a by 7
Hello.
Firstly, let's isolate x on the equation:

Now, we can replace 'x' for 'y' and vice-versa:

Hope I helped.
Answer:
The tree is 17.5 ft tall
Step-by-step explanation:
We can use proportions to solve this.
Notice that Emily (5 feet tall) and her shadow (8 feet long) constitute the two legs of a right angle triangle (see attached image).
The nearby tree (unknown height H), will also cast a shadow (28 ft long) with the same inclination as Emily does due to the unique position of the sun relative to them.
Then we can use the proportion associated with the sides of similar triangles:

Then, we can solve for H in the equation:

Let's interpret this equation. If we have that a runner has 0 races under his belt, he completes the race in 38.1 min. We have that the slope is -1.2 min/race and the intercept at n=0 is 38.1 min. Hence, for every race, the duration of the run decreases by 1.2 min (or increases by -1.2 min).
Lets derive that. Suppose a runner that has run n races, runs once more.
The difference of times is:
(-1.2(n+1)+38.1)-(-1.2n+38.1)=-1.2(n+1)-(-1.2n)= -1.2n-1.2+1.2n=1.2 minutes.
Hence, the correct answer is the first.