4. Let the numbers be x - 2, x, and x + 2, where x is an odd number.
2(x² - 4) - 4x = (x + 2)² + 21
2x² - 8 - 4x = x² + 4x + 4 + 21
2x² - 4x - 8 = x² + 4x + 25
x² - 8x - 33 = 0
(x - 11)(x + 3) = 0
x = 11, or -3
When x = 11, x - 2 = 9, x + 2 = 13
When x = -3, x - 2 = -5, x + 2 = -1
Explanation: You are on the right track. However, rather than having three unknown variables, try to reduce your working out to one unknown variable. Since you know they are consecutive odd numbers, you can simply let x be the middle term and the other two be + and - 2, provided x is an odd number.
That will reduce your variable issues, and helps as the first and third provide a difference of two squares, and this works out very nicely.
Q5: is essentially the same process. Let your variables be something in the form of one unknown variable, and you should be okay from there. Let me know if you're stuck.
The word missing in 12 is fraction and field
the missing word in 14 is dividing
Answer:
f(x) = x² - 2x - 15
Step-by-step explanation:
∵ The function intersect x-axis at -3 and 5
∴ f(x) = 0 at x = -3 , 5
∵ The form of the quadratic equation is ⇒ ax² + -b/a x + c/a = 0
ax² - b/a x + c/a = 0
Where the sum of its roots is b/a and their multiplication is c/a
∵ a = 1
∵ -3 , 5 are the roots of the quadratic equation
∴ b = -3 + 5 = 2
∴ c = -3 × 5 = -15
∴ f(x) = x² - 2x - 15
Answer:
angle B = 33.42
Step-by-step explanation:
take angle B as reference angle
using tan rule
tan B = opposite/adjacent
tan B = 6/9
tan B = 0.66
B = 
B = 33.424
B = 33.42
