CAT 2019 Question Paper (Slot 2) - QUANT Question 17

Question 17

The real root of the equation $$2^{6x} + 2^{3x + 2} - 21 = 0$$ is

Solution

Let $$2^{3x}$$ = v

$$2^{6x} + 2^{3x + 2} - 21 = 0$$

= $$v^2+4v-21=0$$

=(v+7)(v-3)=0

v=3, -7

$$2^{3x}$$ = 3 or $$2^{3x}$$ = -7(This can be negated)

3x=$$\log_23$$

x=$$\log_23$$/3

View Video Solution

video

Comments

Register with

OR

CAT Quant Questions | CAT Quantitative Ability

CAT Linear Equations

CAT Inequalities

CAT Quadratic Equations

CAT Averages, Ratios & Proportions

CAT Profit & Loss

CAT Number Systems

CAT Time, Distance & Work

CAT Progressions & Series

CAT Probability Combinatorics

CAT Venn Diagrams

CAT Data Sufficiency

CAT Logarithms, Surds & Indices

CAT Functions, Graphs & Statistics

CAT Miscellaneous

CAT DILR Questions | LRDI Questions For CAT

CAT Data Interpretation

CAT DI Data Change Over Period

CAT Tables With Missing Values

CAT DI Venn Diagrams

CAT DI Special Charts

CAT DI Maxima & Minima

CAT Quant-Based DI

CAT DI Connected Sets

CAT DI Miscellaneous

CAT LR Arrangement

CAT LR Selections With Conditions

CAT LR Coins & Weights

CAT LR Truth & Lie

CAT LR Scheduling

CAT LR Games & Tournaments

CAT 2D & 3-D LR

CAT Quant-Based LR

CAT LR Miscellaneous

CAT Verbal Ability Questions | VARC Questions For CAT

CAT Reading Comprehension (RC)

CAT Para Jumbles

CAT Para Completion and Summary Questions

CAT Grammar & Sentence Correction

CAT Critical Reasoning

Boost your Prep!

Download App