2.5x - 3 + 2x = 1.75x - 1.25x + 13
4.5x - 3 = 0.50x + 13
4.0x = 16
x = 4
Answer: 4
2. We'll assume those xs are in the numerator
(3/7)x - 1/4 + (3/7)x = (9/7)x - (3/7)x + 3/4 - 1
(6/7)x - 1/4 = (6/7)x - 1/4
0 = 0
That's always true.
Answer: Any x is a solution.
Answer:
12.08
Step-by-step explanation:
For each sunflower, there are only two possible outcomes. Either it germinates, or it does not. The probability of a sunflower germinating is independent of other sunflowers. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
Probability of exactly x sucesses on n repeated trials, with p probability.
The standard deviation of the binomial distribution is:

Seventy-six percent of sunflower seeds will germinate into a flower
This means that 
Samples of 800:
This means that 
The standard deviation for the number of sunflower seeds that will germinate in such samples of size 800 is:

DC/AC=EC/BC
x/(x+3)=10/16
10(x+3)=16x
10x+30=16x
30=6x
x=5
DC=x=5
DC=5 units long
10/16=DE/AB, DE=y
10/16=y/10
16*y=10*10
y=6.25≈6.3
DE≈6.3
I’ve attached a photo of the workings but the answer is 82
AB=√{(6+3)²+(6-2)^2}=√(81+16)=√(97)
BC=√((7-6)²+(-1-6)²)=√(50)=5√2
AC=√((7+3)²+(-1-1)²)=2√(26)
Perimeter=AB+BC+AC=√97+5√2+2√(26)