Simplify and combine like terms...
21b-32+7b-20b
Answers
Answer:
8b -32
Step-by-step explanation:
21b- 32 + 7b - 20b
= 21b - 20b + 7b - 32
= 8b - 32
Ncert solutions
Grade 7
Mathematics
Science
Chapters in NCERT Solutions - Mathematics, Class 7
Exercises in Algebraic Expressions
Question 1
Q1) Simplify combining like terms:
i) 21b-32+7b-20b21b−32+7b−20b
ii) -z^2+13z^2-5z+7z^3-15z−z
2
+13z
2
−5z+7z
3
−15z
iii) p-(p-q)-q-(q-p)p−(p−q)−q−(q−p)
iv) 3a-2b-ab-(a-b+ab)+3ab+b-a3a−2b−ab−(a−b+ab)+3ab+b−a
v) 5x^2y-5x^2+3yx^2-3y^2+x^2-y^2+8xy^2-3y^25x
2
y−5x
2
+3yx
2
−3y
2
+x
2
−y
2
+8xy
2
−3y
2
vi) (3y2+5y-4)-(8y-y2-4)(3y2+5y−4)−(8y−y2−4)
Solution i) 21b-32+7b-20b21b−32+7b−20b
Now, we re-arrange the like terms which gives us
= 21b\ +\ 7b\ -\ 20b\ -\ 3221b + 7b − 20b − 32
= b\left(21\ +\ 7\ -\ 20\right)\ -\ 32b(21 + 7 − 20) − 32
= 8b\ -\ 328b − 32