Answer:
a) ( r+ s) (x) = 3 x + 9
b) ( r . s ) (x) = 2 x² + 13 x +20
c) ( r- s) (x) = -1 -x
Step-by-step explanation:
<u><em>Step(i):-</em></u>
Given that r(x) = x +4 and s(x) = 2x + 5
a) ( r+ s) (x) = r(x) + s(x)
= x +4 + 2x +5
= 3 x + 9
<em> ( r+ s) (x) = 3 x + 9</em>
b)
( r . s ) (x) = r(x) . s(x)
= (x+4) . ( 2x +5)
= x ( 2x +5) + 4( 2x +5)
= 2 x² + 5 x + 8 x +20
= 2 x² + 13 x +20
<em> ( r . s ) (x) = 2 x² + 13 x +20</em>
c)
( r- s) (x) = r(x) - s(x)
= (x+4 - ( 2x +5)
= x +4 - 2x -5
= -x -1
<em> ( r- s) (x) = -1 -x</em>
Answer:
Step-by-step explanation:
Greatest Common Divisor [GCD]: 50
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The question relates to the number of combinations of 9 students taken 6 at a time:
Answer:
The number of gallons of 20% alcohol solution is 12 and the number of gallons of 60% alcohol solution is 4
Step-by-step explanation:
Let
x ----> the number of gallons of 20% alcohol solution
y ----> the number of gallons of 60% alcohol solution
we know that
20%=20/100=0.20
60%=60/100=0.60
30%=30/100=0.30
x+y=16
x=16-y ------> equation A
0.20x+0.60y=16(0.30) ------> equation B
Solve by substitution
Substitute equation A in equation B and solve for y
0.20(16-y)+0.60y=16(0.30)
3.2-0.20y+0.60y=4.8
0.40y=4.8-3.2
0.40y=1.6
y=4 gal
Find the value of x
x=16-y
x=16-4=12 gal
therefore
The number of gallons of 20% alcohol solution is 12 and the number of gallons of 60% alcohol solution is 4
Answer:
169/100
Step-by-step explanation:
93 + 76/100 = 169/100