Answer:
a: 12
b: as much as what?
c: 70
d: 10 times as much
Step-by-step explanation:
a: 4 * 3 = 12
c: 700 / 10 = 70
d: 800 * 10 = 8000
they are straight lines that make a plus
When you have a coefficient in front of the "x^2" value, you have to multiply it by the end value (4)
so you want a set of integers that will add up to 29, by multiple to (7 x 4) = 28
The only numbers like that are 28 and 1, they add up to 29 and multiply to 29
Therefore, rewrite it like this 7x^2 + 28x + x + 4
and then factor out the 7x in the first two terms, to get this
7x(x+4) + x + 4, then factor out 1 in the latter two terms to get this:
7x(x+4) +1(x+4), then use grouping to combine what you've got:
The factors are: {{ (7x+1)(x+4) }}
Answer:

149 engines in 9th year
Step-by-step explanation:
I think your question is missed of key information, allow me to add in and hope it will fit the original one.
Please have a look at the attached photo.
My answer:
From a look at the photo and the data plot can be represented by the function, so we can pick 2 points in our given graph
- (x1, y1) = (2,60)
- (x2, y2) = (5,99)
The standard form of a linear equation is:
y = mx + b where:
- m is the slope
- b is the y-intercept
We know the slope of the function can be found as following:
so in this situation we have:
<=> 
=> y = 13x + b (1)
Because the line goes through point (2,60) so we substitute it into (1):
60 = 13*2 + b
<=> b = 60 - 26 = 34
=> y = 13x + 34
Now we will substitute x=9 to find the engines produced by company in 9th year as:

Hence, the company will produce 149 engines in 9th year