Answer:
x = 9/25
y = 7/25
z = 4/25
Step-by-step explanation:
2x + y = 1 .......(1)
3y + z = 1 ........(2)
x + 4z = 1 ........(3)
Elimination 1 and 2
2x + y = 1 | ×3 |
3y + z = 1 | ×1 |
6x + 3y = 3
3y + z = 1
___________--
6x - z = 2 .............. (4)
Elimination 3 and 4
x + 4z = 1 | ×6 |
6x - z = 2 | ×1 |
6x + 24z = 6
6x - z = 2
___________--
25z = 4
z = 4/25
Elimination 3 and 4
x + 4z = 1 | ×1 |
6x - z = 2 | ×4 |
x + 4z = 1
24x - 4z = 8
___________+
25x = 9
x = 9/25
Subsitution 1
2x + y = 1
2(9/25) + y = 1
18/25 + y = 1
y = 1 - 18/25
y = 25/25 - 18/25
y = 7/25
Answer: C. 18.8w
Step-by-step explanation:
Since Toby exercise 14hours a week, and John exercises 20% more than Toby
John increment in number of hours compared to Tobi will be;
20/100 ×14 = 2.8hrs
This shows John exercises 2.8hrs more than Tobi. Total number of hours exercised by John will become;
14+2.8 = 16.8hrs
Since Jenny exercises two more hours than John, Total number of hours exercised by Jenny will be;
16.8hrs+2hrs
= 18.8hrs/week
If Jenny exercise 18.8hrs in a week, it means she will exercise 18.8×w/1 in w weeks which gives 18.8w weeks.
Answer:
11/12
Step-by-step explanation:
1/4+2/3
1/4×3/3+2/3×4/4
3/12+8/12
1. no because 2x+10 is not equal to 2x+7
2. no. you cant add una like terms so 4x+4 doesn’t equal 8x
3. yes. the terms still retain their same value although they are not in the same order
4. yes. when u distribute the -3, you get -3x-6 which is of course equal to -3x-6
Answer:
(3x+4)(5x+7)
Step-by-step explanation:
15x^2
+41x+28
Factor the expression by grouping. First, the expression needs to be rewritten as 15x^2
+ax+bx+28. To find a and b, set up a system to be solved.
a+b=41
ab=15×28=420
Since ab is positive, a and b have the same sign. Since a+b is positive, a and b are both positive. List all such integer pairs that give product 420.
1,420
2,210
3,140
4,105
5,84
6,70
7,60
10,42
12,35
14,30
15,28
20,21
Calculate the sum for each pair.
1+420=421
2+210=212
3+140=143
4+105=109
5+84=89
6+70=76
7+60=67
10+42=52
12+35=47
14+30=44
15+28=43
20+21=41
The solution is the pair that gives sum 41.
a=20
b=21
Rewrite 15x^2
+41x+28 as (15x^2
+20x)+(21x+28).
(15x^2
+20x)+(21x+28)
Factor out 5x in the first and 7 in the second group.
5x(3x+4)+7(3x+4)
Factor out common term 3x+4 by using distributive property.
(3x+4)(5x+7)
