Answer:
x = -7 or x = 2/3
Step-by-step explanation:
I'm assuming you meant solve for x when f(x) = 0.
f(x) = 3x(x + 7) - 2(x + 7)
0 = (x + 7)(3x - 2) -- Both terms have a common factor of (x + 7) so we can group them
x + 7 = 0 or 3x - 2 = 0 -- Use ZPP
x = -7 or x = 2/3 -- Solve
N; n+1; n+2 - 3 consecutive numbers
n(n + 1) = (n + 2)² - 19 |use a(b + c) = ab + ac and (a + b)² = a² + 2ab + b²
n² + n = n² + 4n + 4 - 19 |subtract n² from both sides
n = 4n - 15 |subtract 4n from both sides
-3n = -15 |divide both sides by (-3)
n = 5
n + 1 = 5 + 1 = 6
n + 2 = 5 + 2 = 7
Answer: 5; 6; 7.
Step-by-step explanation:
Let the marked price of a watch be =₹x
∴ Discount price = x- 20% of x
= x - 0.2x
=0.8x
Amount of VAT = 13% of 0.8x
0.13 x 0.8x
0.104x
Now,
Selling price = 0.8x + 0.104x
∴6328 = 0.904x
x = 0.904 / 6328
x=0.00014285714