This is very simple, you can use tally marks to find the amount of birthdays. Then divide it by 100. Good luck !
From that picture...you already have 3 right angles so the 4 th is also a right angle of 90 degrees
Answer:
3. 35 adults and 420 children
4. The three numbers are 13, 52 and 16
Step-by-step explanation:
3. Let the number of adults be x.
Since there are 12 times more children than adults,
number of children= 12x
Total number of people= 12x +x
13x= 455
x= 455 ÷13
x= 35
12x= 35(12)
12x= 420
Therefore, there are 35 adults and 420 children at the play.
4. Let the first number be x.
Since the 2nd number is 4 times the first,
2nd number= 4x
Third number is 3 more than the first:
3rd number= x+3
sum of numbers= x +4x +x+3
6x +3= 81 (simplify)
6x= 81 -3 (bring constant to 1 side)
6x= 78 (simplify)
x= 78 ÷6
x= 13
Second number
= 4x
= 4(13) (subst. x=13)
= 52 (expand)
third number
= x +3
= 13 +3 (subst. x=13)
= 16
Answer:
37. {-1, -1}.
Step-by-step explanation:
I'll solve the first one . The other can be solved in a similar way. We can use the method of elimination.
x1 - x2 = 0
3x1 - 2x2 = -1
We can multiply the first equation by -2. We then have an equation containing + 2x2 so when we add this to the second equation the 2x2 will be eliminated
So the first equation becomes:
-2x1 + 2x2 = 0 Bring down the second equation:
3x1 - 2x2 = -1 Now adding, we get:
x1 + 0 = -1
so x1 = -1.
Now we substitute this value of x1 in the original first equation:
-1 - x2 = 0
-1 = x2
x2 = -1.
So the solution set is {-1, -1}.
If there are more than 2 equations you can use a combination of substitutions and eliminations.
The product is 3 because -3/4 * -4 is 3
