Answer:
Step-by-step explanation:
The system of equations given are:
5x - y + z = -6 ------------- i
2x + 7y + 3z = 8 ---------- ii
x + 2z = 6 ----------------- iii
Let us deal with equation i and ii first since they have 3 variables x, y and z;
5x - y + z = -6 x 7
2x + 7y + 3z = 8 x 1
35x - 7y + 7z = -42 ---- iv
2x + 7y + 3z = 8 ---- v
Add equation iv and v;
37x + 10z = -34 ------vi
So, let us solve equation vi and iii:
x + 2z = 6 - ---------- iii x 10
37x + 10z = -34 --- iv x 2
10x + 20z = 60 vi
74x + 20z = -68 vii
Subtract vi - vii;
-64x = 128
x = -2
So; put x = -2 into iii;
x + 2z = 6
-2 + 2z = 6
2z = 6 + 2 = 8
z = 4
Put x = -2 and z = 4 into equation i;
5(-2) - y + 4 = - 6
-10 -y +4 = -6
-6 - y = -6
-y = 0
y = 0
Lilla got 21/25 meaning she only missed 4 questions which means she got a 96/100. Tim scored 41/50 meaning he missed 9 questions meaning he got a 91/100 therefore being the reason Lilla got a higher score than Tim being that she has a 96 versus his 91. Hope that helps!!!
Answer:
there is only 1 picture?
Step-by-step explanation:
Step-by-step answer:
Answer to problems of this kind is the reciprocal of the harmonic mean of the time required.
We need to find the average of the speeds, not the average of the time.
The respective speeds are 1/3 and 1/4.
The average of the speeds is therefore (1/3+1/4)/2 = 7/24 (harmonic mean of the time taken).
The time required is therefore the reciprocal of the unit speed,
T = 1/(7/24) = 24/7 = 3 3/7 minutes, or approximately 3.43 minutes.
Answer:
<em>(C).</em> <em>(t² - p)( </em>
<em> + pt² + p²) </em>
Step-by-step explanation:
a³ - b³ = (a - b)(a² + ab + b²)
- p³ = (t²)³ - p³ = <em>(t² - p)( </em><em> + pt² + p²)</em>
