Answer:
D
Step-by-step explanation:
Correct answer is: actual wingspan of airplane is 6 inches.
Solution:-
We are given that wingspan is 'a' feet and tail span is 'b' feet in a scale drawing.
And we are also given that tail span is 2 inches that is b=2 inches and 
Let us plugin the b value in above equation.
Multiplying with 2 on both sides.
a=3X2=6 inches.
Hence actual wingspan of airplane is 6 inches.
<u>Question 8</u>
a^2 + 7a + 12
= (a+3)(a+4)
When factorising a quadratic, the product of the two factors should equal the constant term (12), and the sum of the two factors should equal the linear term (7). To find the two factors, list out the factors of 12 (1x12, 2x6, 3x4) and identify the pair that adds up to 7 (3+4).
An alternative method if you get stuck during your exam would be to solve it algebraically using the quadratic formula and then write it in the factorised form.
a = (-7 +or- sqrt(7^2 - 4(1)(12)) / 2(1)
= (-7 +or- sqrt(1))/2
= -3 or -4
These factors are the negative of the values that would go in the brackets when written in factorised form, as when a = -3 the factor (a+3) would equal 0. (If it were positive 3 instead, then in the factorised form it would be a-3).
<u>Question 10</u>
-3(x - y)/9 + (4x - 7y)/2 - (x + y)/18
Rewrite each fraction with a common denominator so you can combine the fractions into one.
= -6(x - y)/18 + 9(4x - 7y)/18 - (x + y)/18
= (-6(x - y) + 9(4x - 7y) - (x + y)) /18
Expand the brackets and collect like terms.
= (-6x + 6y + 36x - 63y - x - y)/18
= (29x - 58y)/18
= 29/18 x - 29/9 y
10t = b - 4
12b+8t = $348
This is a system of equations. I’ll be solving through substitution.
In the first equation. solving for b (the easier variable to isolate) gives you:
b = 10t + 4
Substitute this into the second equation:
12(10t+4) +8t = 348
120t+48+8t = 348
128t = 300
t = 2.34375 —> round it to the nearest cent to get 2.34 dollars
b = 10t+4
b = 10(2.34)+4
b = 27.4 dollars
Answer:
(x, y) = (- 2, 5)
Step-by-step explanation:
given the 2 equations
3y = 11 - 2x → (1)
3x = y - 11 → (2)
Rearrange (2) expressing y in terms of x
add 11 to both sides
y = 3x + 11 → (3)
Substitute y = 3x + 11 into (1)
3(3x + 11) = 11 - 2x
9x + 33 = 11 - 2x ( add 2x to both sides )
11x + 33 = 11 ( subtract 33 from both sides )
11x = - 22 ( divide both sides by 11 )
x = - 2
Substitute x = - 2 in (3) for corresponding value of y
y = (3 × - 2) + 11 = - 6 + 11 = 5
As a check
substitute x = - 2, y = 5 into (1) and (2) and if the left side equals the right side then these values are the solution.
(1) : left side = (3 × 5) = 15
right side = 11 - (2 × - 2) = 11 + 4 = 15 ⇒ left = right
(2) : left side = (3 × - 2 ) = - 6
right side = 5 - 11 = - 6 ⇒ left = right
solution = (- 2, 5 )
