Answer:
Step-by-step explanation:
Given the simultaneous equation 2p - 3q = 4 and 3p + 2q = 9, to get the value of p and q we will use elimination method.
2p - 3q = 4 ...................... 1 * 3
3p + 2q = 9 ..................... 2 * 2
Multiplying equation 1 by 3 and 3 by 2:
6p - 9q = 12
6p + 4q = 18
Subtracting both equation
-9q-4q = 12-18
-13q = -6
q = -6/-13
q = 6/13
Substituting q = 6/13 into equation 2
2p - 3(6/13) = 4
2p - 18/13 = 4
2p = 4+18/13
2p = (52+18)/13
2p = 70/13
p = 70/26
p = 35/13
<em>Hence p = 35/13 and q = 6/13</em>
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<em>b) </em>If if 223ₓ = 87 find x
Using the number base system and converting 223ₓ to base 2 will give us;
223ₓ = 2*x² + 2*x¹ + 3*x⁰
223ₓ = 2x²+2x+3
Substituting back into the equation, 2x²+2x+3 = 87
2x²+2x+3-87 = 0
2x²+2x-84 = 0
x²+x-42 = 0
On factorizing:
(x²+6x)-(7x-42) = 0
x(x+6)-7(x+6) = 0
(x+6)(x-7) = 0
x+6 = 0 and x-7 = 0
x = -6 and 7
<em>Hence the value of x is 7 (neglecting the negative value)</em>
The amount given to charity from Kendall’s profit is $168.0146
Given:
- Kendall’s profit = $1292.42
- Percentage given to charity = 13%
<h3>How to find percentage</h3>
Amount given to charity = Percentage given to charity × Kendall’s profit
= 13% of $1292.42
= 13/100 × 1292.42
= 0.13 × 1292.42
= $168.0146
Therefore, the amount given to charity from Kendall’s profit is $168.0146
Learn more about percentage:
brainly.com/question/843074
Answer:
- 12k² + kl
Step-by-step explanation:
Given
7kl - 3k(4k + 2l) ← distribute parenthesis by - 3
= 7kl - 12k² - 6kl ← collect like terms
= - 12k² + kl
Solution,
We have,
Width of rectangle, b = (2.5u+9.8) cm
Length of rectangle, l = (1.5u+3.9) cm
We need to find the expression for the perimeter of the rectangle. The formula for the perimeter of a rectangle is given by:
Perimeter = 2(l+b)
P = 2[(2.5u+9.8)+(1.5u+3.9)]
Collecting like terms
P = 2[(2.5u+1.5u)+(9.8+3.9)]
P=2(4u+13.7)
⇒ P = 8u+27.4
So, the expression for the perimeter of the rectangle is (8u+27.4) cm.
