Answer:
C
Step-by-step explanation:
the area of a triangle is
baseline × height / 2
so, we know in our case
b(b+12) = 189 cm²
b² + 12b - 189 = 0
let's try to solve this by completing the square.
that means we try to find the expression
(b + k)² + c
that is equal to
b² + 12b - 189
(b + k)² + c = b² + 2kb + k² + c = b² + 12b - 189
so,
2k = 12
k = 6
and then
k² + c = -189
6² + c = -189
36 + c = -189
c = -225
(b + 6)² - 225 = 0
(b + 6)² = 225
b + 6 = 15
b = 9
so, the baseline b = 9 cm.
the height b+12 = 9+12 = 21 cm.
Answer:
for what?
Step-by-step explanation:
Answer:
Laura is 30 years old and Maria is 18 years old.
Step-by-step explanation:
Let x be the present age of Laura and y be that of Maria.
Laura was 3 times older than Maria when Laura had Maria's present age.
Lets say Laura had Maria's present age(y) k years before.Then Maria's age at that time will be y-k where k=(x-y).
Then:
y=3(y-k)
y=3(y-(x-y))
y=3(2y-x)
3x=5y -------1
After two years Laura will become x+2 years old and 2 years ago Maria was y-2 years old. Then:
x+2=2(y-2)
x=2y-6--------2
Solving 1 and 2 we get:
x=30 and y=18
Hence Laura's present age is 30 and Maria's present age is 18.
Answer:
Input 0 and Output -6
Step-by-step explanation:
The reason why is that we know that -4 has a output of -18 which -3 has a output of -15 meaning each time x increases by 1 the output increases by 3. 1:3 ratio basically so since we know this the starting value should be
y=0+3x
