The equation is 138=300-3x
now solve by first subtracting 300 from each side: -162=-3x
divide each side by -3: x=54
The wise man is 54 years old
Answer:
56.25 pound of the coffee that costs $5 per pound is needed
18.75 pound of the coffee that costs $9 per pound is needed
Step-by-step explanation:
Let the number of pounds be x and y respectively
The total pounds is 75;
So;
x + y. = 75 •••••••(i)
Total cost of first type
9 * x = $9x
Total cost of second type;
5 * y= $5y
75 pound at $6 per pound; total cost of this is;
6 * 75 = $450
Thus;
9x + 5y = 450 ••••••••(ii)
From i, x = 75-y
Put this into ii
9(75-y) + 5y = 450
675 -9y + 5y = 450
4y = 675-450
4y = 225
y = 225/4
y = 56.25
x = 75 - y from i
x = 75-56.25
x = $18.75
Do the exponents first. 10 to the -4 is 1/10000 or 0.0001 and 10^ -5 is 0.00001. You end up with (1.7*0.0001)(5*0.00001) which is 0.00017*0.00005 which is 0.0000000085 or 0.085*10^-8
(b^2+5)(−b^2+7)
Use the FOIL METHOD to expand.
-b^4 + 7b^2 - 5b^2 + 35
-b^4 + 2b^2 + 35
Did you follow?
