Answer:
Here ,
2x-30° +70° +x-10° = 180° ( sum of triangle is 180°)
3x+30 =180°
3x=150°
x=50°
Answer:
Please see attached image and all steps below for both parts
Step-by-step explanation:
Task 1
The following system of equations includes a linear equation and a quadratic one:

it can be solved by using substitution in the second equation of the variable "y" by the linear expression of the first equation:

and this product of two factors will e zero when either factor is zero, that is: when x = 0, or when x = 9 [to make zero the binomial(x - 9)]
There are two solutions: x = 0 and x = 9.
When we graph both expressions in the system, we see that the line intercepts the parabola at the points (0, 2) and (9, 11). See attached image.
Task 2
Part 1:
Let's pick 30 as a number larger than 25. 30 can be written as 40 - 10
So we can use:

to calculate its square.
Part 2:
let's choose a=9 and b=10 so we use:

the answer for this is:
subtract 7 from 4 to get -3
you then have 2^-3
remove the negative exponent by rewriting as 1/(2^3)
Answer:
Area of floor = 21.6m2
area of tile = 576cm2=0.0576m2
now,
number of tiles = 21.6/0.0576
= 375