I think it might be minus 1/4
Answer:
A. 3x^2+7x^2+2×3x ×7-84x = 3x^2+7x^2-2×3x×7
9x^2+49x^2+42x-84 x= 9x^2+49x^2-42x
9x^2+49x^2-42 = 9x^2+49 x^2-42x
verified
B.
Answer:
The correct answer is option C.
Sin 45 degrees = square root of 2 divided by 2, cos 45 degrees = square root of 2 divided by 2, tan 45 degrees = 1
Step-by-step explanation:
The sin cos tan table used to calculate values of the ratios for different angles can be used for the values.
The table is easily available on the internet.
WE can use a a right-angles isosceles triangle to find the exact values for the angle 45.
The equal sides have length 1. So the thirs side using the pythagoras theorem will be √2.
So
Sin 45 = √2/2
Cos 45 = √2/2
and
Tan 45 = 1
So the correct option is C.
Multiply by 4 and rearrange.
... 4y -4 = x - 12
... -4 = x - 4y - 12 . . . . . . subtract 4y
... x - 4y = 8 . . . . . . . . . . add 12. This is standard form.