Answer:
Rotation about 90° counter clockwise (x , y) →→ ( -y, x ).
Step-by-step explanation:
Given : Triangle XYZ has vertices X(1, 3), Y(0, 0), and Z(–1, 2). The image of triangle XYZ after a rotation has vertices X'(–3, 1), Y'(0, 0), and Z'(–2, –1).
To find : Which rule describes the transformation.
Solution : We have given
vertices X(1, 3) →→ X'(–3, 1)
Y(0, 0) →→ Y'(0, 0),
Z(–1, 2) →→ Z'(–2, –1).
Here , we can see in each coordinates value of y become -x and x become y.
(x , y) →→ ( -y, x ) this the rule of rotation about 90° counter clockwise.
Therefore, rotation about 90° counter clockwise (x , y) →→ ( -y, x ).
Answer:
a)7x - 10
b) 70 g
Step-by-step explanation:
a)
Mass of 1st chemical which was mixed = 10g
Mass of 2nd chemical which was mixed = 2x
Mass of 3rd chemical which was mixed = 5x-20
So total mass of the the mixture which was formed after mixing all the 3 chemicals are =
10 + 2x + 5x - 20
=> 7x - 10
b)
Mass of the mixture = 235 g
From (a) , we know that
7x - 10 = 235
=> 7x = 235 + 10 = 245
=> x = 245 / 7 = 35
Hence x = 35
We also know that mass of the 2nd chemical was = 2x.
So putting the value of x gives :-
2 × 35 = 70 g