Solution :
2a + 2b = 7 ...1)
4a + 3b = 12 ...2)
In equation, 1)
a = (7 - 2b)/2 ...3)
Putting value of a in equation 2) we get :
4 × (7 - 2b)/2 + 3b = 12
2( 7 - 2b ) + 3b = 12
14 - 4b + 3b = 12
b = 2
Putting value of b in 3) we get :
a = ( 7 - 2×2)/2
a = 3/2 = 1.5
Now,
2x - 3y = 16 ...5)
x + 2y = -6 ...6)
x = -6 - 2y
Putting above value of x in eq 5) , we get :
2( -6 - 2y ) - 3y = 16
-12 - 4y - 3y = 16
7y = -28
y = -4
x = -6 - ( 2× -4 )
x = 2
Hence, this is the required solution.
Answer:
The number of adults is 
Step-by-step explanation:
Let
x------> the number of children
y------> the number of adults
we know that
-------> equation A
-------> equation B
Multiply equation A by 
-------->
------> equation C
Adds equation B and equation C

Answer:
The time taken by Allan to complete the marathon 3.5 hours
Step-by-step explanation:
Given as :
The distance cover in marathon = d = 26.2 miles
∵ 1 mile = 1.609 km
So, d = 26.2 × 1.609 km
i.e d = 42.155 kilo meter
The average speed of Allan = s = 12 km per hour
Let the time taken by Allan to complete the marathon = t hours
Now, ∵ Time = 
Or, t = 
Or, t = 
or, t = 3.512 hours
So , The time taken by Allan to complete the marathon = t = 3.5 hours
Hence, The time taken by Allan to complete the marathon 3.5 hours Answer
Answer:
common ratio=0.5, a1= 0.08
Step-by-step explanation:
r=a3/a2
r=a4/a3
compare both we get:
a3/a2=a4/a3
subtitute a2=0.04 and a4=1
a3/0.04=1/a3
(a3)^2=0.04*1
(a3)^2=0.04
taking square root in both sides
a3=0.02
For r, r=a3/a2
subtitute a3 and a2 above
r=0.02/0.04
r=0.5 common ratio
For a1
r=a2/a1
0.5=0.04/a1
a1=0.04/0.5
a1=0.08
Forty and ninety nine hundreths