Answer:
3306.5
Step-by-step explanation:
What do you need help with. I am really good in math
Answer:
Sister = 15 years old
Brother = 12 years old
Step-by-step explanation:
Right now, if the brother is B years old and the sister is S years old, B = (4/5)S because the ratio from brother to sister is 4:5, so if one unit is X, B = 4X and S = 5X
Three years ago, the brother was B-3 years old and the sister was S-3 years old. Keeping one unit as X, we have
B = 3X
S = 4X
B-3 = (3/4)(S-3)
Therefore, we have a system of equations
B = (4/5)S
B-3 = (3/4)(S-3)
Substitute (4/5)S for B into the second equation to only have one variable
(4/5)S - 3 = (3/4)(S-3)
(4/5)S - 3 = (3/4)S - 9/4
add 3 to both sides and subtract (3/4)S from both sides to isolate the variable and its coefficient
(1/20)S = 3/4
multiply both sides by 20 to isolate the S
S = 15
B = (4/5)S = 12
Answer:
Cartesian Coordinate System
• Also called
rectangular coordinate
system
• x- and y- axes intersect
at the origin
• Points are labeled (x,y)
Polar Coordinate System
– Origin and reference
line are noted
– Point is distance r from
the origin in the
direction of angle θ,
ccw from reference
line
– Points are labeled (r,θ)
Cartesian to Polar Coordinates
• r is the hypotenuse and θ
an angle
θ must be ccw from
positive x axis for these
equations to be vali
Step-by-step explanation: