Area = Length * Width = l * w
l = x + 2
w = 2x - 5
Area = (x + 2)(2x - 5) = 56
Area = 2x^2 -x - 10 = 56
Area = 2x^2 - x - 66 = 0 Now you have to factor this thing.
Area = (2x + 11)( x - 6) = 0 This is more or less done by guessing.
2x + 11 = 0 can't work. x would be negative.
x - 6 = 0
x = 6.
Check
=====
l = x + 2
l = 6 + 2
l = 8
w = 2*x - 5
w = 2*6 - 5
w = 12 - 5
w = 7
l*w = 8*7 = 56. It checks.
If this is the best answer you get, could you consider a Brainly? I need 2 of them to move up.
Consider this option:
1. if to re-write the condition, it is given: total time t=8 hours; upstream=downstream=6 miles; V_boat=4 m/h., V_current=V=?
2. note, that total time=time_upstream+time_downstream, where time_upstream=6miles/(V_boat-V) and time_downstream=6miles/(V_boat+V). Using this it is possible to make up and solve the following equation:

answer: √10
P.S. the roots of the equation are √10 and (-√10), only positive values is needed for V.
Answer:
2
Step-by-step explanation:
So I'm going to use vieta's formula.
Let u and v the zeros of the given quadratic in ax^2+bx+c form.
By vieta's formula:
1) u+v=-b/a
2) uv=c/a
We are also given not by the formula but by this problem:
3) u+v=uv
If we plug 1) and 2) into 3) we get:
-b/a=c/a
Multiply both sides by a:
-b=c
Here we have:
a=3
b=-(3k-2)
c=-(k-6)
So we are solving
-b=c for k:
3k-2=-(k-6)
Distribute:
3k-2=-k+6
Add k on both sides:
4k-2=6
Add 2 on both side:
4k=8
Divide both sides by 4:
k=2
Let's check:
:


I'm going to solve
for x using the quadratic formula:







Let's see if uv=u+v holds.

Keep in mind you are multiplying conjugates:



Let's see what u+v is now:


We have confirmed uv=u+v for k=2.
Answer:
55°
Step-by-step explanation:
triangle= 180°
third angle= 180-90-35
= 55°
1. 15/3:3/3
2. 5:1
1. find the same denominator
2. divide by denominator