Given :-
- a² - 2a - b² = 0
- 2b + 2ab = 0
To find :-
Solution :-
<u>Taking</u><u> </u><u>second</u><u> </u><u>equation</u><u>:</u><u>-</u>
- 2b + 2ab = 0
- 2b ( 1 + a ) = 0
- 2b = 0 or (1+a) = 0
- b = 0 , a = -1
<u>Substitute</u><u> </u><u>in </u><u>first </u><u>equation</u><u> </u><u>:</u><u>-</u><u> </u>
<u>When </u><u>b </u><u>=</u><u> </u><u>0</u><u> </u><u>,</u>
- a² - 2a - 0² = 0
- a² - a = 0
- a( a -1) =0
- a = 0 , 1
<u>When </u><u>a </u><u>=</u><u> </u><u>-</u><u>1</u><u> </u><u>,</u>
- (-1)² - 2*(-1) - b² = 0
- 1 + 2 - b² = 0
- b² = 3
- b = ±√3
<u>Answer </u><u>:</u><u>-</u><u> </u>
- a = 0,1 ; b = 0
- a = -1 , b = ±√3
Answer:10 gallons of 30% solution and 30 gallons of 70% solution should be mixed.
Step-by-step explanation:
Let x represent the number of gallons of the 30% solution that should be mixed.
Let y represent the number of gallons of the 70% solution that should be mixed.
The total number of gallons of the mixture to be made is 40. This means that
x + y = 40
The 30% solution of fertilizer is to be mixed with a 70% solution of fertilizer in order to get 40 gallons of a 60% solution. This means that
0.3x + 0.7y = 0.6 × 40
0.3x + 0.7y = 24- - - - - - - - - - - - - -1
Substituting x = 40 - y into equation 1, it becomes
0.3(40 - y) + 0.7y = 24
12 - 0.3y + 0.7y = 24
- 0.3y + 0.7y = 24 - 12
0.4y = 12
y = 12/0.4
y = 30
x = 40 - y = 40 - 30
x = 10
Moving the decimal point one place is a factor of ten; two places is a factor of 100
So 100.
NB; three places would be 1000
After 4 hours there will be 64 000
3 - 32k
2-16
1-8
do you need exactly 50 000?
Decimals because money is expressed in decimals and we handle with money every day.