So dad is represented by x
son is represented by y
so x is (x=) 7 times his son (7y)
our first sentence is x=7y
10 years later (x+10, y+10) he will be 3 times as old as his son (x+10=3(y+10))
or 10+x=3(y+10)
so our sentences are
x=7y
and
x+10=3(y+10)
first we subsitute x=7y for x in the second equation
(7y)+10=3(y+10)
7y+10=3(y+10)
we distribute
7y+10=3y+30
subtract 3y from both sides
4y+10=30
subtract 10 from both sides
4y=20
divide both sides by 4
y=5
the son is currently 5 years old
x=7y
subsitute y=5 for y in equation
x=7(5)
x=35
the dad is currently 35 years old
in 10 years
dad is 45 and son is 15
dad=35
son=5
Answer:
Option A
Step-by-step explanation:
Option A
f(x) = -3(x + 7)(x + 4),
Remember that to solve for the x-intercepts we equate y to 0,
-3(x + 7)(x + 4) = 0
Using the zero product property,
x + 7 = 0, x + 4 = 0
x = - 7, x = -4
x -intercepts: (- 7, 0) & (- 4, 0)
Hence proved.
Okay I quick key to multiplying with 0 is anything multiplied by 0 equals zero. So 9÷14=.64. .64×0=0. ANSWER: 0
I believe you line the decimals up, the biggest number goes on top and the smallest on bottom .
