Answer:
14 hours
Step-by-step explanation:
Let's call the task 3x
The older bro does twice as younger so it would be 2x long and younger brother work x long
Since the totsl of work is 3x = 21 x woul be 21÷3 = 7
the older brother must work 2 × 7 = 14 hours long
Answer:
356.53
Step-by-step explanation:
Calculate the semicircle and square areas separately. For the semicircle, A = πr²/2, so 100.53
And for the square, A = a², so 256
Hope this helps
1. To solve this exercise, you must make a system of equations.
2. You have that f<span>our times a number minus twice another number is -8:
</span>
4x-2y=-8
3. And t<span>he sum of the two number is 19:
</span>
x+y=19
4. As you can see, you have two equations:
4x-2y=-8 (i)
x+y=19 (ii)
5. Let's clear the "x" from the equation (ii):
x=19-y
6. Now, you need to susbtitute x=19-y into the equation (i):
4x-2y=-8
4(19-y)-2y=-8
76-4y-2y=-8
76-6y=-8
-6y=-8-76
-6y=-84
y=-84/-6
y=14
7. You must susbstitute y=14 into the equation (ii) and clear "x":
x+y=19
x+14=19
x=19-14
x=5
The answer is: 5 and 14
