1.Consider the system of equations. x-5y=2
3x-10y=11
(a) Jamar rewrote the first equation as –2x + 10y = –4. What justification did he have for doing this?
(b)Jamar combined the equation in Part (a) with the second equation in the system to get x = 7. Explain Jamar’s reasoning.
(c) What is the solution of the system? (d) How do you know, without graphing, that the graph of 4x – 15y = 13 passes through the point whose coordinates are the solution of the system?
Answer:
9² = 40² + 41² - 2(40)(41) cos(C)
81 = 1600 + 1681 - 3280 cos(C)
81 = 3281 - 3280 cos(C)
-3200 = -3280 cos(C)
cos(C) = 3200 / 3280
cos(C) = 40 / 41
Step-by-step explanation:
Answer:
36
Step-by-step explanation:
Whenever something is to the power of 2, just think of the number multiplied twice :) Hoped this helped.
The formula for the quadratic formula is x (c in this case) = (-b(+/-)√(b²-4ac))/2a
This is used for an equation in standard quadratic form: ax² + bx + c = 0
1.) Put it in the correct form, if not already in it.
Ex. c² + 6c + 8 = 0
2.) Identify each part of the equation:
a = 1 (the leading coefficient), b = 6 (the coefficient in front of the second variable), c = 8
3.) Plug in each variable answer
c = (-6(+/-)√(6²-4(1)(8))/2(1)
4.) Simplify
c = (-6(+/-)√(36-(4*8))/2
c = (-6(+/-)√(36-32))/2
c = (-6(+/-)√(4))/2
c = (-6(+/-)2)/2
*Here, the equation splits in two. It becomes:
c = (-6+2)/2 AND c = (-6-2)/2
*Simplify again:
c = -4/2 AND c = -8/2
c = -2 AND c = -4
The answers c = -2 and c = -4 would solve the given equation.
Hope this helps! :)
Answer:
Step-by-step explanation:
Use proportions to solve.
Corresponding sides have same ratio.
<u>Question 1</u>
- (6x + 3)/17 = (8x - 1)/21
- 21(6x + 3) = 17(8x - 1)
- 126x + 63 = 136x - 17
- 10x = 80
- x = 8
<u>Question 2</u>
- (x + 8)/21 = 32/28
- x + 8 = 21*8/7
- x + 8 = 24
- x = 24 - 8
- x = 16