<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
Answer:
porfavor en español pls para yo poder resolverlo
Answer:
No, it is equal
Step-by-step explanation:
30% of 720 is 216.
Answer: Draw a line through the two points (0,2) and (3,3). See the attached image below.
How did I get these two points? The first point comes from the fact that "at the start, the height is 2 inches" meaning that x = 0 hours and y = 2 inches pair up together. This is show as point A. This is the y intercept as this is the location where the blue graph crosses the vertical y axis.
Point B is found by moving 1 unit up from point A and 3 units to the right to land on (3,3). So we have x = 3 hours and y = 3 inches pair up together.
Note: the slope is rise/run = 1/3 helping us determine the unit rate or speed in which the water is rising (ie the water is rising one-third of an inch per hour)
Answer:
what is the question?
Step-by-step explanation:
all u have is the numbers
